JP2003258766A - Receiving device, transmitting device, communication system and communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately apply spatial diversity combining to a multi-carrier CDMA transmission system, reduce the influence of interference between information channels, and improve signal transmission characteristics. SOLUTION: A plurality of antennas 51 _{1 to} 51 n are signals obtained by multiplying a plurality of information symbols by a spreading code for each of information channels # 1 to #n, and are transmitted by a plurality of subcarriers. Receive the signal. Spreading code multiplying section 52e multiplies received signal 7 by a spreading code of the information channel corresponding to received signal 7. The weight control unit 8 adjusts the antenna weight and the subcarrier weight. The antenna weight multiplication unit 52f and the subcarrier weight multiplication unit 54 multiply the reception signal 7 by the antenna weight and the subcarrier weight. Antenna signal combining section 53 and symbol combining section 55
Synthesizes the reception signal 7 multiplied by the antenna weight and the subcarrier weight between the antennas and over the spreading code period of the spreading code.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a receiving device, a transmitting device, a communication system, and a communication method.

[0002]

2. Description of the Related Art Multi-Carrier Code Division Multiple Access
Transmission method, hereinafter "multi-carrier CDMA transmission method"
Was proposed in 1993, and thereafter its application to mobile communication systems has been studied (for example, see Non-Patent Document 1). In the multi-carrier CDMA transmission system, information symbols are duplicated in the frequency axis direction, each duplicated information symbol is multiplied by one chip of a spreading code to be spread, and the spread information signal is parallelized by a plurality of subcarriers having different frequencies. It is a transmission method for transmission.

The multi-carrier CDMA transmission system can simultaneously transmit a plurality of information symbols. Further, in the multi-carrier CDMA transmission system, information symbols are multiplied by spreading codes in the frequency axis direction. Therefore, in the multi-carrier CDMA transmission system, code multiplexing of a plurality of information symbols can be realized by multiplying the information symbols by orthogonal spreading codes.

Further, in the multi-carrier CDMA transmission system, since parallel transmission is performed by using a plurality of subcarriers,
The symbol rate is reduced and the symbol length is increased. As a result, the multicarrier CDMA transmission system can reduce the influence of so-called multipath interference, which is a problem in the mobile communication environment. With multipath interference, transmitted signals arrive at a receiving device at different timings through a plurality of different transmission paths (multipath transmission paths), and the arriving signals interfere with each other to deteriorate signal transmission characteristics. Say that. In a multipath transmission line, frequency-selective fading in which variations in the transmission line vary depending on frequency occurs, and signal transmission quality changes depending on frequency. But,
In the multi-carrier CDMA transmission system, information signals are spread in the frequency axis direction. Therefore, multi-carrier C
In the DMA transmission method, due to the frequency diversity effect,
The effect of changing the signal transmission quality is reduced and the signal transmission characteristics are improved. Thus, the multi-carrier CDMA transmission system has many advantages.

On the other hand, the multicarrier CDMA transmission system has the following problems. As shown in FIG. 42,
The receiving device receives the signal transmitted by multiplexing the signals of the information channel # 1 and the information channel # 2. The receiver is
The received signal is multiplied in the frequency direction by the same spread code as the spread code multiplied by the transmitter. Next, the receiving device performs despreading by combining the received signals of the respective subcarriers over the spreading code period of the spreading code.

As shown in FIG. 42 (a), when the propagation path fluctuation value of each subcarrier is constant, the spreading codes multiplied by the information symbols of each information channel are orthogonal to each other. Therefore, the received signal after despreading is the information channel # 1, #
The information symbol 2 is completely restored. However, in reality, as shown in FIG. 42B, each subcarrier undergoes different amplitude fluctuations and phase fluctuations, so the propagation path fluctuation value is not constant. Therefore, the orthogonality between the spread codes multiplied by the received signal of each information channel propagated through the multipath propagation path is lost. As a result, the received signal after despreading has the information channel #
The information symbols of 1 and # 2 cannot be completely restored, and the information symbols of other information channels interfere and remain. Therefore, the signal transmission characteristic deteriorates.

In order to solve such a problem, a method has been proposed in which a receiving apparatus multiplies a received signal for each subcarrier by a weight and combines the received signals to reduce interference of information symbols between information channels. (See, for example, Non-Patent Document 2).

On the other hand, there is diversity combining as a technique for reducing the influence that the signal transmission quality changes depending on the frequency due to the above frequency selective fading and improving the signal transmission characteristics. One type of diversity combining is space diversity combining in which signals are received by a plurality of antennas, the received signals of the respective antennas are multiplied by weights, and the signals are combined between the antennas. Further, a method for multiplying weights in the space diversity combination has also been proposed (see Non-Patent Document 3, for example).

In recent years, orthogonal frequency division multiplexing (OF)
DM: Orthogonal Frequency and Code Division
It has been proposed to apply spatial diversity combining to a multiplexing) multicarrier transmission system (for example, see Non-Patent Document 4).

[0010]

[Non-Patent Document 1] N. Yee, 2 others, "MULTI-CARRIER C
DMA IN INDOOR WIRELESS RADIO NETWORKS ", Pers
onal Indoor and Mobile Radio Communications,
IEEE, September 8-11, 1993, p. 109-113

[0011]

[Non-Patent Document 2] Hara, 1 outside, “Design and Pe
rformance of Multicarrier CDMA System in Fre
quency-Selective Rayleigh Fading Channels ”, IE
EETRANSCATIONS ON VEHICULAR TSCHNOLOGY, IEEE,
September 1999, VOL. 48, NO. 5, p. 1584-
1595

[0012]

[Non-patent Document 3] D. G. Brennan, “Linear Diversity
Combining Techniques ", Proceedings of the I
RE, IRE, June 1959, VOL. 47, NO. 6, p. 1
075-1102

[0013]

[Non-Patent Document 4] Munster, 2 outside, "CO-CHANNEL
INTERFERENCE SUPPRESSION ASSISTED ADAPTIVE OFD
M IN INTERFERENCE LIMITED ENVIRONMENTS ", Ve
hicular Technology Conference-Fall, IEEE, 199
September 19-22, 1997, p. 284-288

[0014]

However, conventionally, the application of the spatial diversity combination to the orthogonal frequency division multiplexing multicarrier transmission system has only been examined, and the spatial diversity combination to the multicarrier CDMA transmission system has been studied. The application of was not examined at all.

Therefore, the present invention provides a multi-carrier CDM.
Appropriately applying spatial diversity combining to the A transmission system,
It is an object of the present invention to reduce the influence of interference between information channels and improve signal transmission characteristics.

[0016]

A receiving apparatus according to the present invention is a signal obtained by multiplying a plurality of information symbols transmitted on a plurality of information channels by a spreading code for each information channel, A plurality of antennas for receiving signals transmitted by a plurality of subcarriers having different frequencies, and a spread code multiplication unit for multiplying a received signal received by the plurality of antennas by a spread code of an information channel corresponding to the received signal, , A weight control unit for adjusting the antenna weight to be multiplied by the received signal for each antenna and the subcarrier weight for multiplying the received signal for each subcarrier, and the antenna weight and subcarrier weight adjusted by the weight control unit as the received signal. A weight multiplication unit for multiplying, and a received signal obtained by multiplying the antenna weight and the subcarrier weight by the weight multiplication unit And a combining unit for combining over the period.

According to such a receiving apparatus, a plurality of antennas are signals obtained by multiplying a plurality of information symbols by a spread code for each information channel, and are transmitted by a plurality of subcarriers having different frequencies. Received signal. A spread code multiplication unit multiplies the received signal by the spread code of the information channel corresponding to the received signal. The weight multiplication unit
The reception signal is multiplied by the antenna weight that is multiplied by the reception signal for each antenna adjusted by the weight control unit and the subcarrier weight that is multiplied by the reception signal for each subcarrier. Then, the combining unit combines the received signal multiplied by the antenna weight and the subcarrier weight, between the antennas and over the spreading code period of the spreading code.

Therefore, the received signal is multiplied by the antenna weight and the subcarrier weight adjusted by the weight controller.
Therefore, the spread codes of the information channels multiplied by the received signal are orthogonal to each other. As a result, the information symbols are reduced in the influence of interference between the information channels caused by the break in the orthogonality between the spreading codes. As described above, the receiving apparatus can appropriately apply the spatial diversity combining to the multi-carrier CDMA transmission system to improve the signal transmission characteristics.

Further, it is preferable that the weight controller adjusts the antenna weight and the subcarrier weight so that the spread codes of the plurality of information channels are orthogonal to each other. According to this, the received signal is multiplied by the weight and the antenna weight and the subcarrier weight adjusted so that the spreading codes of the plurality of information channels are orthogonal to each other. Therefore, the spread codes of the information channels multiplied by the received signal can be more reliably made orthogonal to each other.

Further, the weight controller preferably adjusts the antenna weight and the subcarrier weight so that the spread codes of the plurality of information channels are orthogonal to each other and the signal power to noise power ratio becomes large. . According to this, the receiving device determines that the signal power to noise power ratio (S
Since the NR (Signal to Noise Power Ratio) can be increased, the influence of noise can be reduced and the signal transmission characteristics can be further improved.

The weight control unit adjusts the antenna weight and the subcarrier weight to individually determine the antenna weight and the subcarrier weight, and the weight multiplication unit multiplies the received signal for each antenna by the antenna weight. An antenna weight multiplication unit and a subcarrier weight multiplication unit that multiplies the received signal for each subcarrier by the subcarrier weight, and the combining unit combines the received signals in which the antenna weights are multiplied between the antennas. And a symbol synthesizing unit for synthesizing the received signal multiplied by the subcarrier weight over the spreading code period.

According to this, the receiving apparatus obtains the antenna weight, multiplies the received signal for each antenna by the antenna weight, synthesizes the received signal between the antennas, obtains the subcarrier weight, and obtains each subcarrier. It is possible to individually perform the processing of multiplying the received signal of 1 by the subcarrier weight and combining the received signal over the spreading code period. As a result, the weight controller can determine the antenna weight in consideration of the process of multiplying the received signal by the subcarrier weight and combining the received signals over the spreading code period. Further, the weight control unit can determine the subcarrier weight in consideration of a process of multiplying the received signal by the antenna weight and combining the received signals between the antennas.

The weight control unit adjusts the antenna weight and the subcarrier weight to determine a collective weight for collectively multiplying the received signals, and the weight multiplying unit determines the received signal for each subcarrier of each antenna. May be multiplied by the collective weight, and the combining unit may collectively combine the received signals multiplied by the collective weight over the antennas and over the spreading code period. According to this, the receiving device can collectively perform the process of obtaining the weight, the process of multiplying the weight, and the process of combining the received signals. Therefore, the process performed by the receiving device can be simplified. Also, the configuration of the receiving device can be simplified.

Further, the receiving apparatus multiplies the received signal for each subcarrier multiplied by the spreading code by the subcarrier weight, synthesizes the spread signals over the spreading code period, and multiplies the received signal for each antenna by the antenna weight. It is preferable to include a determination unit that controls the order of combining between the antennas, and the weight multiplication unit and the combining unit perform despreading based on the control of the determination unit and perform space diversity combining.

According to this, the determination unit performs multiplication of the subcarrier weight for the received signal for each subcarrier multiplied by the spreading code included in the despreading process, and combination of the spread code period and space diversity combination. The order of multiplication of the received signal for each antenna included in the processing by the antenna weight and the combination between the antennas is controlled. Then, the weight multiplication unit and the combining unit perform the respective processes in the order according to the control of the judging unit, and perform despreading and space diversity combining. Therefore,
The receiving apparatus can perform each processing included in the despreading and spatial diversity combining processing in an appropriate order suitable for the situation at that time. Therefore, the receiving device can further improve the signal transmission characteristics.

Further, the receiving device comprises a measuring section for measuring the state of the received signal received by the plurality of antennas, and the judging section controls the order of each processing based on the state of the received signal measured by the measuring section. Preferably. According to this, the determination unit, based on the state of the received signal measured by the measurement unit,
The order of each process can be controlled. Therefore, the receiving apparatus can perform each process included in the process of despreading and space diversity combining in an appropriate order according to the state of the received signal of each antenna.

In the subcarrier weight multiplication unit, the antenna weight multiplication unit multiplies the reception signal for each antenna by the antenna weight, and the antenna signal combination unit combines the reception signals multiplied by the antenna weight. After performing diversity combining, the received signal for each subcarrier multiplied by the spread code is multiplied by the subcarrier weight, and the symbol combining unit performs spatial diversity combining and then the received signal multiplied by the subcarrier weight. It is preferable to perform de-spreading, which is synthesized over the spreading code period.

According to this, the subcarrier weight multiplying unit and the symbol combining unit individually multiply the received signals of the plurality of antennas by the subcarrier weights, and the process of combining the received signals over the spread code period. You don't have to. That is, the subcarrier weight multiplying unit and the symbol synthesizing unit collectively process the received signals synthesized between the plurality of antennas by the subcarrier weights, and the process of synthesizing the received signals over the spreading code period. It can be performed.

In this case, the antenna weight multiplication unit multiplies the reception signal of each antenna by the antenna weight before separating the reception signal into the reception signal of each subcarrier, and the antenna signal combining unit divides the reception signal into subcarriers. It is preferable to combine the reception signals multiplied by the antenna weights between the antennas before separating the reception signals for each. According to this, the receiving apparatus does not need to individually perform the process of separating the received signal into the received signals of each subcarrier for each of the received signals of the plurality of antennas. That is, the receiving device can collectively perform processing for collectively dividing the received signals into the received signals for each subcarrier, with respect to the received signals combined between the plurality of antennas.

In the antenna weight multiplication unit, the spreading code multiplication unit multiplies the received signal by the spreading code of the information channel corresponding to the received signal, and the subcarrier weight multiplication unit subcarriers the received signal for each subcarrier. After performing despreading in which the symbol combining unit multiplies the weights and the reception signal multiplied by the subcarrier weights is spread over the spreading code period, the reception signal for each antenna is multiplied by the antenna weight, and the antenna signal combining unit It is preferable to perform space diversity combining in which the received signal multiplied by the antenna weight is combined between the antennas after despreading is performed.

According to this, the weight control unit multiplies the spread code, the sub-carrier weight, and the received signal after being combined over the spread code period, that is, after despreading. The antenna weight can be determined in consideration of the influence of interference between the information channels in the received signal. Then, the weight multiplication unit multiplies the antenna weight. Finally, the antenna signal combining unit combines the received signals, which are multiplied by the antenna weights obtained in consideration of the influence of interference between the information channels, between the antennas. Therefore, the receiving apparatus can more appropriately reduce the influence of the interference between the information channels of the information symbols, and can further improve the signal transmission characteristics.

In this case, it is preferable that the weight controller determines the antenna weight based on the received signal combined by the symbol combiner over the spreading code period. According to this, the weight control unit can actually determine the antenna weight in consideration of the influence of the interference between the information channels in the reception signal which is multiplied by the subcarrier weight and is combined over the spreading code period. Therefore, it is possible to more appropriately reduce the influence of interference between information channels of information symbols,
The signal transmission characteristics can be further improved.

Further, the receiving device is provided with a channel condition estimating section for estimating the condition of the channel in which the transmitted signal propagates,
The weight control unit preferably adjusts the antenna weight and the subcarrier weight based on the estimated value of the channel condition estimated by the channel condition estimation unit. According to this, the receiving apparatus can appropriately determine the antenna weight and the subcarrier weight according to the propagation path situation. Therefore, the receiving device can further improve the signal transmission characteristics.

Further, the receiving device is provided with an interference condition estimating unit for estimating the condition of interference in the received signal, and the weight control unit is
The antenna weight and the subcarrier weight may be adjusted based on the estimated value of the interference situation estimated by the interference situation estimation unit. According to this, the receiving apparatus can appropriately determine the antenna weight and the subcarrier weight according to the interference situation of the received signal. Therefore, the receiving device can further improve the signal transmission characteristics.

Further, the receiving device comprises a reception quality measuring section for measuring the reception quality of the information symbol restored from the received signal, and the weight control section, based on the measured value of the reception quality measured by the reception quality measuring section, The antenna weight and the subcarrier weight may be adjusted. According to this, the receiving apparatus can appropriately determine the antenna weight and the subcarrier weight according to the reception quality of the information symbol.
In particular, the receiving apparatus can feed back the received quality of the restored information symbol to the antenna weight and the subcarrier weight. Therefore, the receiving device further
The signal transmission characteristics can be improved.

Further, the receiving apparatus may be provided with an adding section for adding the received signals for each subcarrier and averaging them in the frequency direction or the time axis direction. According to this, when the addition unit averages the received signals in the frequency direction, the weight multiplication unit can multiply the received signals by the antenna weight and the subcarrier weight after averaging in the frequency direction. Therefore, the weight control unit can reduce the number of antenna weights and subcarrier weights to be determined, and can reduce the load of processing to determine weights. Further, since the number of weight multiplication units provided in the receiving device can be reduced, the configuration of the receiving device can be simplified. When the adder averages the received signals in the time axis direction, the received signals for each subcarrier are averaged in the time axis direction, and the averaged received signals are combined over the spread code cycle. However, the signal power to noise power ratio of the received signal obtained by despreading can be increased.

Further, the transmitting apparatus according to the present invention divides an information symbol transmitted on a plurality of information channels into a plurality of information symbols, and a plurality of information symbols divided by the dividing unit, A symbol duplicating unit that duplicates a number equal to the spreading code period of the spreading code corresponding to the information channel to be transmitted, and the information symbol duplicated by the symbol duplicating unit is multiplied by the spreading code corresponding to the information channel transmitting the information symbol. A spreading code multiplying unit that serves as an information signal, a spreading unit that spreads the information signal multiplied by the spreading code by the spreading code multiplying unit onto a plurality of subcarriers having different frequencies for transmitting the information signal, and the spreading unit includes a plurality of sub-carriers. For each information signal spread on the carrier, a guard interval insertion unit for inserting a guard interval for preventing interference between the information signals is provided. It is characterized in.

According to such a transmission device, the division unit divides the information symbols transmitted on the plurality of information channels into a plurality of information symbols. The symbol duplication unit duplicates the information symbols by the number equal to the spreading code period of the spreading code corresponding to the information channel transmitting the information symbol. A spreading code multiplication unit multiplies the duplicated information symbol by a spreading code corresponding to the information channel to obtain an information signal. Then, the spreading unit spreads the information signal on a plurality of subcarriers having different frequencies. Furthermore, the guard interval insertion unit inserts a guard interval for each information signal spread over a plurality of subcarriers. Therefore, the transmitter can simultaneously transmit a plurality of information signals of a plurality of information channels by using a plurality of subcarriers having different frequencies. Further, the transmitting device can reduce the influence of interference of a plurality of information signals that arrive at the receiving device after being delayed due to the influence of multipath propagation. Therefore,
The transmitter can improve the transmission characteristics.

Further, it is preferable that the transmitting apparatus includes a pilot symbol inserting section for inserting pilot symbols whose amplitude and phase are known in the receiving apparatus for receiving the information signal into the information symbol. According to this, the transmitter is
Pilot symbols whose amplitude and phase are known in the receiving device can be transmitted to the receiving device together with information symbols. Therefore, the receiving device compares the actually received pilot symbol with the pilot symbol that is supposed to be transmitted from the transmitting device of which the amplitude and phase are known, and determines the propagation path fluctuation amount of the pilot symbol and the received signal. The error between the despread pilot symbol and the transmitted pilot symbol can be obtained.

Then, the receiving apparatus can perform channel estimation using the propagation path fluctuation amount of the pilot symbol. Here, the propagation path fluctuation amount means the fluctuation amount and the amplitude of the phase that the signal transmitted by the transmitting device has changed until the receiving device receives the signal by propagating in the propagation path between the transmitting device and the receiving device. Refers to the fluctuation amount of. That is, the propagation path fluctuation amount is how much the phase and the amplitude fluctuate before the signal transmitted by the transmitting device propagates through the propagation path between the transmitting device and the receiving device 5 and is received by the receiving device. Indicates. or,
In this way, estimating the channel fluctuation amount of the received signal
This is called channel estimation. Therefore, the channel fluctuation amount of the received signal obtained by the channel estimation is particularly referred to as "channel estimation value". Further, the receiving apparatus can estimate the error between the received signal and the transmitted signal after despreading, using the error of the pilot symbol. Therefore, the receiving apparatus can determine the subcarrier weight or the collective weight to be multiplied by the received signal using the channel estimated value or the estimated value of the error between the received signal and the transmitted signal after despreading.

Further, the pilot symbol inserting section inserts, into the information symbol, the channel fluctuation amount estimating pilot symbol used for estimating the channel fluctuation amount of the information signal in the receiving apparatus. In the inserting section and the receiving device, a weight updating pilot symbol used for estimating an error between the information signal received by the receiving device after despreading and the information signal transmitted by the transmitting device is inserted into the information symbol. And a pilot symbol inserting section for use.

According to this, the pilot symbol inserting section for estimating the channel fluctuation amount and the pilot symbol inserting section for updating the weight are separately provided. Therefore, the transmitter is
Separately transmit the optimal pilot symbol for estimating the amount of channel fluctuation and the optimal pilot symbol for updating the weight to estimate the error between the despread received signal and the transmitted signal. can do. Further, the transmitter can generate a transmission signal by a multiplexing method suitable for each pilot symbol.

Also, in the communication system according to the present invention, a signal obtained by multiplying a plurality of information symbols transmitted on a plurality of information channels by a spread code for each information channel is used to generate a plurality of subcarriers having different frequencies. A communication device comprising a transmitting device for transmitting by means of a transmitting device and a receiving device for receiving a signal transmitted by the transmitting device, wherein the receiving device comprises a plurality of antennas for receiving signals, and a received signal received by a plurality of antennas, A spreading code multiplication unit that multiplies the received signal by the spreading code of the information channel, and a weight control unit that adjusts the antenna weight that multiplies the received signal for each antenna and the subcarrier weight that multiplies the received signal for each subcarrier ,
The weight multiplication unit that multiplies the received signal by the antenna weight and the subcarrier weight adjusted by the weight control unit, and the received signal that the weight multiplication unit multiplies the antenna weight and the subcarrier weight by the spread code period between the antennas and the spread code. And a synthesizing unit for synthesizing the same.

Further, the communication method according to the present invention is a signal obtained by multiplying a plurality of information symbols transmitted on a plurality of information channels by a spread code for each information channel, and a plurality of signals having different frequencies. The signal transmitted by the subcarrier is received by a plurality of antennas of the receiving device, the receiving device multiplies the received signal received by the plurality of antennas by the spread code of the information channel corresponding to the received signal, and Adjust the antenna weight to be multiplied to the received signal of and the subcarrier weight to be multiplied to the received signal for each subcarrier,
It is characterized in that the adjusted antenna weights and subcarrier weights are multiplied by the received signals, and the received signals multiplied by the antenna weights and subcarrier weights are combined between the antennas and over the spreading code period of the spreading code.

According to such a communication method, the received signal is multiplied by the adjusted antenna weight and subcarrier weight. Therefore, the spread codes of the information channels multiplied by the received signal are orthogonal to each other. As a result, the information symbols are reduced in the influence of interference between the information channels caused by the break in the orthogonality between the spreading codes. Therefore, according to such a communication method, it is possible to appropriately apply the space diversity combination to the multicarrier CDMA transmission system and improve the signal transmission characteristic.

Further, when the receiving apparatus adjusts the antenna weight and the subcarrier weight, it is preferable that the receiving apparatus adjust the antenna weight and the subcarrier weight so that the spread codes of the plurality of information channels are orthogonal to each other. Furthermore, when the receiving device adjusts the antenna weight and the subcarrier weight, the spreading factors of the plurality of information channels are orthogonal to each other, and the signal power to noise power ratio is increased so that the antenna weight and the It is preferable to adjust the subcarrier weight.

Further, the receiving apparatus adjusts the antenna weight and the subcarrier weight to individually determine the antenna weight and the subcarrier weight, multiplies the received signal for each antenna by the antenna weight, and receives between the antennas. Combine the signals, multiply the received signal for each subcarrier by the subcarrier weight,
It is preferable to combine the received signals over the spreading code period.

Further, the receiving device adjusts the antenna weight and the subcarrier weight to determine the collective weight for collectively multiplying the received signals, and multiplies the collective weight by the received signal for each subcarrier of each antenna. The received signals multiplied by the collective weight may be collectively combined between the antennas and the spread code period.

Further, the receiving device multiplies the received signal for each subcarrier multiplied by the spreading code by the subcarrier weight, synthesizes the spread signals over the spreading code period, and multiplies the received signal for each antenna by the antenna weight. It is preferable to control the order of combining between the antennas, perform despreading based on the control, and perform space diversity combining. Further, in this case, it is preferable that the receiving device measures the states of the reception signals received by the plurality of antennas and controls the order based on the measured states of the reception signals.

Further, the receiving apparatus multiplies the received signal for each antenna by the antenna weight, and after performing space diversity combining for combining the received signal multiplied by the antenna weight between the antennas, the sub-code multiplied by the spread code is performed. It is preferable to perform despreading in which the received signal for each carrier is multiplied by the subcarrier weight and the received signal multiplied by the subcarrier weight is combined over the spreading code period. In this case, the receiving device multiplies the reception signal of each antenna by the antenna weight before separating the reception signal into the reception signal of each subcarrier, and synthesizes the reception signal multiplied by the antenna weight between the antennas. Is preferred.

Further, the receiving apparatus multiplies the received signal by the spread code of the information channel corresponding to the received signal, multiplies the received signal for each subcarrier by the subcarrier weight, and the reception by the subcarrier weight is multiplied. After despreading, which combines signals over spreading code periods, multiplies the received signal for each antenna by the antenna weight, and combines the received signal multiplied by the antenna weight between the antennas to perform spatial diversity combining. You may do it. In this case, the receiving device preferably determines the antenna weight based on the received signal combined over the spreading code period.

Further, when performing despreading after performing spatial diversity combining, the receiving device maintains the state of the received signal multiplied by the antenna weight based on the antenna weight by which the received signal is multiplied, or It is preferable to determine whether to adjust the state of the received signal multiplied by the antenna weight again, and adjust the subcarrier weight based on the determination result. Also, when performing despreading after performing spatial diversity combining, the receiving apparatus determines the antenna weight using the equal gain combining method, and uses either the minimum mean square error combining method or the equal gain combining method. It is preferable to determine the subcarrier weight.

When performing spatial diversity combining after despreading, the receiving apparatus maintains the state of the received signal multiplied by the subcarrier weight based on the subcarrier weight by which the received signal is multiplied. Alternatively, it is preferable to determine whether to adjust the state of the received signal multiplied by the subcarrier weight again and adjust the antenna weight based on the determination result. Also, the receiving device, after performing the despreading,
When performing spatial diversity combining, it is preferable to determine the subcarrier weight using the minimum mean square error combining method, and to determine the antenna weight using the equal gain combining method.

Further, it is preferable that the receiving apparatus estimates the condition of the propagation path on which the transmitted signal propagates, and adjusts the antenna weight and the subcarrier weight based on the estimated value of the propagation path condition. In this case, the receiving apparatus compares the threshold value of the channel condition, which is the criterion for adjusting the antenna weight and the subcarrier weight, with the estimated value of the channel condition, and based on the comparison result, the antenna weight and the subcarrier weight. Is preferably adjusted.

Further, the receiving apparatus may estimate the interference situation in the received signal and adjust the antenna weight and the subcarrier weight based on the estimated value of the interference situation. In this case, the receiving device compares the threshold value of the difference in the interference situation between the antennas, which is the criterion for adjusting the antenna weight and the subcarrier weight, and the difference in the estimated value of the interference situation between the antennas, and It is preferable to adjust the antenna weight and the subcarrier weight based on the above.

Further, the receiving apparatus may measure the reception quality of the information symbol restored from the received signal and adjust the antenna weight and the subcarrier weight based on the measured value of the reception quality. In this case, the receiving apparatus compares the threshold value of the variation amount of the reception quality, which is the criterion for adjusting the antenna weight and the subcarrier weight, with the variation amount of the measurement value of the reception quality, and based on the comparison result, the antenna weight is determined. And adjusting the subcarrier weights.

[0057]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] (Communication System) As shown in FIG.
Includes a transmitter 4 and a receiver 5. Transmitter 4
Are provided in the base station 2, for example. The receiving device 5 is provided in the terminal device 3, for example. The transmitter 4 transmits a signal obtained by multiplying a plurality of information symbols transmitted on a plurality of information channels by a spread code by using a multi-carrier CDMA transmission system that transmits a plurality of subcarriers having different frequencies. Send. The receiving device 5 receives the signal transmitted by the transmitting device 4 by the multicarrier CDMA transmission method. The communication system is not limited to the one-to-one communication between the transmitting device 4 and the receiving device 5 as shown in FIG. 1, but the transmitting device 4 and the receiving device 5 are in one-to-many communication, or the transmitting device 4 and the receiving device. The communication system 5 may be a multiple-to-one communication, and the transmitting device 4 and the receiving device 5 may be a multiple-to-multiple communication.
Further, the communication system may be a communication system in which the transmitter 4 and the receiver 5 relay signals to other transmitters 4 and receivers 5.

[0059] As shown in (transmission device) 2, the transmission device 4 includes a plurality of signal processing units ₄₁ 1 _~41n, a pilot symbol inserting unit 41h, a signal combining unit 42, a frequency-time conversion unit 43, A guard interval insertion unit 44 and an antenna 45 are provided. The signal processing units 41 _{1 to} 41 n are
The number of a plurality of information channels # 1 to #n is provided. And
The signal processing unit 41 ₁ corresponding to the respective information channels #. 1 to # n
.About.41n perform processing of transmission signals such as information signals and pilot signals transmitted on the information channels # 1 to #n.

[0060] The signal processing unit ₄₁ 1 _~41n includes information symbol generating unit 41a, an error correction coding unit 41b, a data modulator 41c, a serial-parallel converter 41d, a spreading code generating unit 41e, a plurality of symbols The duplication unit 41f and a plurality of spread code multiplication units 41g are provided.

The information symbol generator 41a generates information symbols to be transmitted on the information channel. That is, the information symbol generator 41a of each of the signal processors 41 _{1 to} 41n.
Generates information symbols corresponding to each of the information channels # 1 to #n. The information symbol generation unit 41a uses the terminal device 3
It generates data such as images to be transmitted to the user and information symbols of voice. The information symbol generation unit 41a can use, for example, an information symbol generation circuit that generates information symbols.

The error correction coding unit 41b, for the information symbol generated by the information symbol generation unit 41a,
Perform error correction coding. The error correction coding unit 41b performs, for example, turbo coding or convolutional coding. According to this, the receiving device 5 can perform error correction decoding. Therefore, the receiving device 5 can obtain the coding gain (the amount of improvement in which the required received power is reduced by applying the error correction code), and the communication quality can be improved.

The data modulator 41c performs a data modulation process on the information symbols that have been subjected to error correction coding. The data modulation unit 41c uses a 16QAM (Quadrature
Amplitude Modulation) and multi-valued quadrature amplitude modulation such as 64QAM, BPSK (Binary Phase Shift Keying)
Modulation, QPSK (Quadrature Phase Shift Keying)
Modulate.

The serial / parallel conversion section 41d is a division section for dividing an information symbol into a plurality of information symbols. The serial-parallel converter 41d serial-parallel converts the information symbols in order to simultaneously transmit a plurality of information symbols. Specifically, the serial-parallel conversion unit 41d divides the serial information symbols input from the data modulation unit 41c into fixed intervals and converts the serial information symbols into information symbols arranged in parallel in the frequency axis direction.

The symbol duplication section 41f includes a serial / parallel conversion section 4
1d performs serial-parallel conversion and divides multiple information symbols into
A number equal to the spreading code period of the spreading code corresponding to the information channels # 1 to #n for transmitting the information symbol is duplicated.

The spread code generator 41e generates spread codes corresponding to the information channels assigned to the information channels. The spread code generation unit 41e inputs the generated spread code to the spread code multiplication unit 41g.

The spreading code multiplying unit 41g multiplies the information symbols duplicated by the symbol duplicating unit 41f by the spreading codes corresponding to the information channels # 1 to #n for transmitting the information symbols to obtain an information signal. The spreading code multiplication unit 41g
The spread code input by the spread code generation unit 41e multiplies each duplicated information symbol in the frequency axis direction. The spreading code multiplication units 41g are provided in the same number as the spreading code period of the spreading code corresponding to the information channels # 1 to #n for transmitting the information symbol. The spreading code multiplying unit 41g inputs the information signal obtained by multiplying the information symbol by the spreading code, to the signal combining unit 42.

Pilot symbol inserting section 41h inserts pilot symbols into information symbols in order to generate transmission signal 6 in which information signals and pilot signals are multiplexed. The pilot symbol is a symbol whose amplitude and phase are known in the receiving device 5. The pilot symbol is used in the receiving device 5 for estimating the propagation path fluctuation amount of the received signal and the error between the received signal and the transmitted signal after despreading. The pilot symbols consist of multiple information channels # 1.
Common pilot symbols may be used in #n, or different pilot symbols may be used in each information channel # 1 to #n.

The transmitter 4 performs code multiplexing for multiplexing the pilot signal and the information signal in the spreading code axis direction. Therefore, a pilot signal inserting unit 41h, together with the signal processing unit ₄₁ 1 _~41n of a plurality of information channels #. 1 to # n, pilot signals of different spreading codes and the signal processing unit ₄₁ 1 _~41n obtained by multiplying the pilot symbols Is input to the signal combining unit 42. In this way, inserting the pilot symbol includes not only the case of inserting the pilot symbol itself but also the case of inserting the pilot symbol after multiplying the pilot symbol by a spreading code.

[0070] The signal synthesizing unit 42 synthesizes the information signals of the respective information channel #. 1 to # n input from the spreading code multiplication section 41g of the signal processing unit ₄₁ 1 _~41n of each information channel,
Code multiplex. In the transmitting device 4, each information channel # 1 to
Not only the information signal of #n but also the pilot signal is input to the signal combining unit 42 by the pilot symbol inserting unit 41h. Therefore, the signal combining unit 42 combines the information signal and the pilot signal and code-multiplexes them.

In the frequency-time conversion section 43, the spread code multiplication section 41g multiplies the spread code and the signal synthesis section 42 code-multiplexes the information signal to spread to a plurality of subcarriers having different frequencies for transmitting the information signal. It is a diffusion unit. The frequency-time conversion unit 43 performs frequency-time signal conversion on the information signal,
The information signal is allocated to a plurality of subcarriers having different frequencies to generate a multicarrier CDMA signal. The frequency-time conversion unit 43 may be, for example, an IFFT device (Inverse F).
ast Fourier Transform) or the like can be used to perform inverse fast Fourier transform processing.

The guard interval inserting section 44 inserts a guard interval for each information signal spread by the frequency / time converting section 43 into a plurality of subcarriers. The guard interval prevents interference between information signals and is inserted between the information signals. By inserting a guard interval, it is possible to reduce the influence of each information signal delayed by the influence of multipath propagation and reaching the reception device 5 and interfering between the information signals. The guard interval insertion unit 44 can insert, for example, a signal obtained by copying a part of the waveform of the information signal or a signal having a predetermined pattern as the guard interval. Further, the length of the guard interval can be determined in consideration of the delay time.

The antenna 45 transmits the multi-carrier CDMA signal in which the guard interval is inserted as the transmission signal 6 to the receiving device 5. Since the transmitter 4 code-multiplexes the pilot signal and the information signal, as shown in FIG. 3A, the pilot signal 62a and the information signal 61a are code-multiplexed in the spreading code axis direction by different spreading codes. It becomes the signal 6a. Further, the transmission signal 6a becomes a multi-carrier CDMA signal which is spread in the frequency axis direction, that is, spread in the frequencies of a plurality of subcarriers. In this way, when the pilot signal 62a and the information signal 61a are code-multiplexed, the time of the transmission signal 6a of one frame can be shortened and the frame efficiency can be improved.

The pilot signal and the information signal may be multiplexed by time multiplexing in the time axis direction. When time multiplexing is performed, for example, the transmitting device 204 shown in FIG. 4 can be used. The transmitter 204 time-multiplexes the pilot signal and the information signal. In transmitting apparatus 204, the signal processing unit ₂₄₁ 1 _~241n information symbol generating unit 41a, error correction coding unit 41b, data modulator 41
c, the spread code generation unit 41e and the frequency time conversion unit 43,
The guard interval insertion unit 44 and the antenna 45 are shown in FIG.
It is substantially the same as the transmitter 4 shown in FIG. Therefore, in FIG. 4, the same reference numerals as those of the transmission device 4 are given and the description thereof is omitted.

In the pilot symbol inserting section 241h, the data modulating section 41c converts the information symbol into a serial / parallel converting section 241.
The pilot symbol is input to the serial-parallel conversion unit 241d at a time different from the time input to d. By this means, information symbols and pilot symbols are time-multiplexed. Specifically, as shown in FIG. 5, the information symbol output from the data modulator 41c and the pilot symbol inserter 2
The switching unit 241i for switching the pilot symbol output from 41h and inputting it to the serial-parallel conversion unit 41d.
Thus, the information symbol and the pilot symbol are input to the serial-parallel converter 241d at different times.

The serial-parallel converter 241d converts the time-multiplexed information symbols and pilot symbols into serial-parallel converter 4
Serial-parallel conversion is performed in the same manner as 1d. Symbol duplication unit 24
1f duplicates the time-multiplexed information symbol and pilot symbol in the same manner as the symbol duplicating unit 41f.
Then, the spreading code multiplying unit 241g adds the time-multiplexed information symbol and pilot symbol to the spreading code multiplying unit 4
In the same manner as for 1g, a spread code is multiplied to form a time-multiplexed information signal and pilot signal. Each information channel # 1
The #n spreading code multiplication unit 241g inputs the time-multiplexed information signal and pilot signal, which are multiplied by the spreading code, to the signal combining unit 242. Signal combining unit 242, each information channel #. 1 to # n input from the spreading code multiplication section 241g of the signal processing unit ₂₄₁ 1 _~241n of each information channel
Of the time-multiplexed information signal and pilot signal,
Code multiplex.

As a result, the transmission signal 6b transmitted by the transmission device 204 becomes a transmission signal in which the pilot signal 62b and the information signal 61b are time-multiplexed in the time axis direction, as shown in FIG. 3 (b). Further, since the time-multiplexed information signal and pilot signal are multiplied by the spread code and code-multiplexed, the transmission signal 6b is the multi-carrier CDMA in which the pilot signal 62b is code-multiplexed together with the information signal 61b.
Become a signal. In this way, when the pilot signal 62b and the information signal 61b are time-multiplexed, the inter-symbol interference does not occur in the pilot signal 62b as shown in FIG. 3 (b).
Therefore, the receiving device 5 receives the received pilot signal 62.
In the case of estimating the channel fluctuation amount and the error between the reception signal after despreading and the transmission signal 6 by using b, the estimation accuracy can be improved.

Further, the pilot signal and the information signal may be multiplexed by frequency multiplexing in the frequency axis direction. When frequency multiplexing is performed, for example, the transmitter 30 shown in FIG.
4 can be used. The transmitter 304 frequency-multiplexes the pilot signal and the information signal. Transmitting device 304
In, the information symbol generator 41a, the error correction encoder 41b, the data modulator 41c, the serial-parallel converter 41d, and the spread code generator 41 of the signal processors 341 _{1 to} 341n.
e, the symbol duplication unit 41f and the frequency time conversion unit 43,
The guard interval insertion unit 44 and the antenna 45 are shown in FIG.
It is substantially the same as the transmitter 4 shown in FIG. Therefore, in FIG. 6, the same reference numerals as those of the transmission device 4 are given and the description thereof is omitted.

Pilot symbol insertion section 341h inputs pilot symbols to spreading code multiplication section 341g. The pilot symbol insertion unit 341h does not input pilot symbols to all of the plurality of spread code multiplication units 341g, but inputs them at several intervals. That is, the pilot symbol insertion unit 341h inputs pilot symbols to some spread code multiplication units 341g among the plurality of spread code multiplication units 341g. As a result, the pilot symbol is inserted at a specific frequency, and the information symbol and pilot symbol are frequency-multiplexed. The spreading code multiplication unit 341g in which the pilot symbol is inserted multiplies the information symbol and the pilot symbol by the spreading code in the same manner as the spreading code multiplication unit 41g.
Spread code multiplication unit 341g of each information channel # 1 to #n
Inputs the frequency-multiplexed information signal obtained by multiplying the spread code and the pilot signal to the signal combining unit 342. The signal combiner 342 is a signal processor 341 for each information channel.
The frequency-multiplexed information signals of the information channels # 1 to #n and the pilot signals input from the spread code multiplication units 341g of _{1 to} 341n are combined and code-multiplexed.

As a result, the transmission signal 6c transmitted by the transmission device 304 becomes a transmission signal in which the pilot signal 62c and the information signal 61c are multiplexed in the frequency axis direction, as shown in FIG. 3 (c). In addition, since the frequency-multiplexed information signal and pilot signal are code-multiplexed, the transmission signal 6
c is a multi-carrier CDMA signal in which the pilot signal 62c is code-multiplexed together with the information signal 61c. In this way, when the pilot signal 62c and the information signal 61c are frequency-multiplexed, the time of the transmission signal 6c of one frame can be shortened and the frame efficiency can be improved.

The pilot signal may be transmitted in a signal form different from that of the information signal. As the spreading code to be multiplied by the pilot symbol, a spreading code common to a plurality of information channels # 1 to #n may be used, or a different spreading code may be used for each information channel # 1 to #n.

(Receiving Device) As shown in FIG. 7, the receiving device 5 includes a plurality of antennas 51 _{1 to} 51 n, a plurality of signal processing units 52 _{1 to} 52 n, a weight control unit 8, and an antenna signal combining unit 53. And a plurality of subcarrier weight multiplication units 54,
A plurality of symbol combining units 55, a serial / parallel converting unit 56, a data demodulating unit 57, an error correction decoding unit 58, and an information symbol restoring unit 59 are provided.

[0083] a plurality of antennas 51 ₁ ~51n is transmitted from the transmission device 4, a plurality of information symbols transmitted by a plurality of information channels #. 1 to # n, obtained by multiplying a spreading code for each information channel A multicarrier CDMA signal transmitted by a plurality of subcarriers having different frequencies. Hereinafter, the antennas 51 _{1 to} 5
The signal received by 1n is referred to as a received signal 7. The received signal 7 includes not only an information signal but also a pilot signal and a guard interval.

The signal processing units 52 _{1 to} 52 n are provided in the same number as the plurality of antennas 51 _{1 to} 51 n. Each antenna 51
_The signal processing units 52 _{1 to} 52 n corresponding to ₁ to 51 n receive the multi-carrier C received by the antennas 51 _{1 to} 51 n.
The received signal 7, which is a DMA signal, is processed. The signal processing unit ₅₂ 1 _~52n, the symbol timing synchronization unit 52a
A guard interval removing unit 52b, a time frequency converting unit 52c, a spreading code generating unit 52d, a plurality of spreading code multiplying units 52e, and a plurality of antenna weight multiplying units 52f.

[0085] The symbol timing synchronization unit 52a for each reception signal 7 by the antenna ₅₁ 1 _~51n received, to establish synchronization of the symbol timing. The guard interval removing unit 52b removes the guard interval inserted in the received signal 7.

The time-frequency converter 52c performs time-frequency conversion on the received signal 7 and separates the received signal 7 spread on a plurality of subcarriers having different frequencies into the received signal 7 for each subcarrier. The time frequency conversion unit 52c is, for example, F
An FT device (Fast Fourier Transform) or the like can be used, and fast Fourier transform processing can be performed.

The spread code generator 52d generates a spread code similar to the spread code by which the received signal 7 is multiplied. That is, the spread code generator 52d generates spread codes for the information channels # 1 to #n that transmitted the received signal 7. The spreading code generation unit 52d uses the generated spreading code as the spreading code multiplication unit 5
Enter in 2e.

The spread code multiplication unit 52e multiplies the received signal 7 received by the plurality of antennas 51 _{1 to} 51n by the spread code of the information channel corresponding to the received signal 7. The spread code multiplication unit 52e multiplies the received signal 7 for each subcarrier separated by the time-frequency conversion unit 52c by the spread code of the information channels # 1 to #n that transmitted the received signal 7 in the frequency axis direction. By being multiplied by the spread code in this way, the influence of the spread code multiplied by the transmitter 4 is removed from the received signal 7. As a result, the information signal and pilot signal included in the received signal 7 become information symbols and pilot symbols. The spreading code multiplication units 52e are provided by the number of subcarriers. Each spreading code multiplication unit 5
2e multiplies the received signal 7 for each subcarrier by a spreading code. The spread code multiplication unit 52e inputs the received signal multiplied by the spread code to the antenna weight multiplication unit 52f.

The weight controller 8 controls the received signal 7 for each antenna.
And the weight (hereinafter referred to as “antenna weight”) by which the received signal 7 for each subcarrier is multiplied (hereinafter referred to as “subcarrier weight”). The antenna weight is the received signal 7 before being separated for each subcarrier,
There are a weight to be multiplied for each antenna and a weight to be multiplied for each antenna on the received signal 7 after being separated for each subcarrier. Further, the subcarrier weight is a weight by which the received signal 7 before being combined between the antennas is multiplied by each subcarrier and a weight by which the received signal 7 after being combined between the antennas is multiplied by each subcarrier. There is.

Here, the inventor et al.
When the application of space diversity combining to the MA transmission system is examined, when the receiving device simply multiplies the received signal for each subcarrier of each antenna by weight and combines the signals between the antennas, the following problems occur. was there. As shown in FIG. 8, when the received signals for each subcarrier of each antenna are simply multiplied by weights and combined between the antennas, the power of the received signals for each subcarrier after combining between the antennas is combined between the antennas. In some cases, the frequency may fluctuate more than before. In this case, the orthogonality between the spread codes multiplied by the information signal is greatly lost. Then, the received signal for each subcarrier after combining between the antennas is multiplied by the spread code, and combined for the spread code period and despread, the obtained information symbols after despreading are Interference between information channels increases due to the loss of orthogonality. That is, in some cases, simply applying the space diversity combination to the multi-carrier CDMA transmission system may significantly deteriorate the signal transmission characteristics.

Therefore, it is important that the weight control unit 8 adjusts the antenna weight and the subcarrier weight so that the spread codes of the plurality of information channels # 1 to #n are orthogonal to each other. Therefore, the weight control unit 8 sets the antenna weight and the subcarrier weight to a plurality of information channels # 1 to #.
The n spread codes are adjusted so as to be orthogonal to each other. The weight control unit 8 preferably has a plurality of information channels # 1 to #n.
The antenna weights and subcarrier weights are adjusted so that the spread codes of are orthogonal to each other and the signal power to noise power ratio (SNR) is large. According to this, the receiving device 5
Since the SNR of the received signal 7 can be increased, the influence of noise can be reduced and the signal transmission characteristic can be further improved.

The weight control unit 8 adjusts the antenna weight and the subcarrier weight to individually obtain the antenna weight and the subcarrier weight. The weight control unit 8 includes an antenna weight control unit 81 and a subcarrier weight control unit 82.
The antenna weight controller 81 calculates the antenna weight and inputs the antenna weight to the antenna weight multiplier 52f. The subcarrier weight controller 82 calculates the subcarrier weight,
The subcarrier weight is input to the subcarrier weight multiplication unit 54. The antenna weight multiplication unit 52f and the subcarrier weight multiplication unit 54 configure a weight multiplication unit that multiplies the received signal 7 by the antenna weight and the subcarrier weight adjusted by the weight control unit 8. The antenna signal combining unit 53 and the symbol combining unit 55 configure a combining unit that combines the received signal 7 multiplied by the antenna weight and the subcarrier weight by the weight multiplying unit, between the antennas and over the spreading code period of the spreading code.

The antenna weight multiplication unit 52f is used by the antenna 5
The received signal 7 for each of 1 _{1 to} 51n is multiplied by the antenna weight. The antenna weight multiplication unit 52f includes the signal processing units 52 ₁ to 52 ₁ .
The reception signals 7 received by the antennas 51 _{1 to} 51 n where 52 n performs signal processing are multiplied by the antenna weight. The antenna weight multiplication units 52f are provided by the number of a plurality of subcarriers. Each antenna weight multiplication unit 52f receives the reception signal 7 for each subcarrier input from each spreading code multiplication unit 52e.
To the antenna weight. Each of the signal processing units 52 _{1 to} 52
The n antenna weight multiplication units 52f each input the received signal 7 multiplied by the antenna weight to the antenna signal synthesis unit 53.

The subcarrier weight multiplication unit 54 multiplies the received signal 7 for each subcarrier by the subcarrier weight. The subcarrier weight multiplication units 54 are provided in the same number as a plurality of subcarriers. Each subcarrier weight multiplication unit 54 multiplies the received signal 7 for each subcarrier input from the antenna signal synthesis unit 53 by the subcarrier weight. Each subcarrier weight multiplication unit 54 inputs the received signal 7 for each subcarrier multiplied by the subcarrier weight to the symbol combination unit 55.

The antenna signal synthesizing section 53 includes the antenna 51.
_The received signal 7 is combined between _{1 and} 51n. Antenna signal combining unit 53 combines the reception signals 7 input from the antenna weight multiplying unit 52f of the respective signal processing unit 52 ₁ ~52n among the antennas. Thus, the antenna weight multiplied to the received signal 7 each antenna 51 ₁ ~51n received, by combining among the antennas, space diversity combining is performed. The symbol combining unit 55 combines the received signal 7 over the spread code period. The plurality of symbol combiners 55 spread the received signal 7 for each subcarrier input from the subcarrier weight multiplier 54 over the spreading code period of the spreading code of the information channels # 1 to #n corresponding to the received signal 7. To synthesize. In this way, despreading is performed by multiplying the received signal 7 for each subcarrier that has been multiplied by the spreading code by the subcarrier weight and synthesizing over the spreading code period.
The symbol combining unit 55 inputs the combined reception signal 7 to the serial-parallel conversion unit 56.

In the receiving device 5, the spread code multiplication unit 52e
However, after the received signal 7 for each subcarrier is multiplied by the spread code, the antenna weight multiplication unit 52f causes the antennas 51 _{1 to} 5
The received signal 7 for every 1n is multiplied by the antenna weight. Then, the antenna signal combining unit 53 causes the antennas 51 _{1 to} 51 ₁
Received signals 7 are combined between n to perform space diversity combining. After that, the subcarrier weight multiplication unit 54 multiplies the reception signal 7 for each subcarrier combined between the antennas 51 _{1 to} 51 n by the subcarrier weight. Finally, the symbol synthesizing unit 55 synthesizes the received signal 7 over the spreading code period and performs despreading. As a result of combining by the symbol combining unit 55, the information symbol before being multiplied by the spreading code in the transmitting device 4 is restored.

The serial / parallel conversion unit 56 includes a symbol combining unit 55.
By this, the information symbols that have been combined and restored over the spreading code period are parallel-serial converted. The serial-parallel conversion unit 56 is a connection unit that connects a plurality of information symbols into one information symbol. The serial-parallel conversion unit 56 is divided into fixed intervals,
The information symbols arranged in parallel in the frequency axis direction are concatenated and converted into one information symbol arranged in series.

The data demodulation section 57 performs data demodulation processing on the information symbols parallel-serial converted by the serial-parallel conversion section 56. The data demodulation unit 57 includes transmitters 4, 20.
Data demodulation processing is performed according to the modulation performed by the 4,304 data modulators 41c.

The error correction decoding unit 58 includes a data demodulation unit 57.
Performs an error correction decoding process on the information symbol subjected to the data demodulation process. The error correction decoding unit 58 performs an error correction decoding process in accordance with the error correction coding performed by the error correction coding unit 41b of the transmission device 4, 204, 304. According to this, the receiving device 5 can obtain the coding gain and improve the communication quality.

The information symbol restoration section 59 restores the information symbols, which have been subjected to the error correction decoding processing by the error correction decoding section 58, to a state in which they can be output to an output device such as a display or a speaker, and outputs them to the output device. . This allows
Data such as images and sound are output.

Next, the antenna weight controller 81 and the subcarrier weight controller 82 will be described in detail. As the antenna weight control unit 81, for example, FIG.
The antenna weight control units 811 to 813 shown in (c) can be used.

As shown in FIG. 9A, the antenna weight controller 811 includes a signal power comparator 811a and a selector 81.
1b and. Signal power comparison unit 811a detects the power of the received signal 7 in which a plurality of antennas ₅₁ 1 _~51n received and compared. The signal power comparison unit 811a detects, as the power of the reception signal 7, the power of the reception signal 7 itself, the power of the signal obtained by removing the influence of noise from the reception signal 7, and the like.
Compare.

According to the comparison result, the signal power comparison unit 811a sets the antenna weight 811c to "1" as the weight of the reception signal 7 of the antenna having the reception signal 7 of the maximum power, and the reception signals 7 of other antennas. The antenna weight 811c is set to "0". The selection unit 811b selects the reception signal 7 of the antenna having a weight of "1" according to the antenna weight 811c. Therefore, the selection unit 811b selects only the reception signal 7 of the antenna having the reception signal 7 of the maximum power.

The antenna weight controller 811 inputs the determined antenna weight 811c to the antenna weight multiplier 52f. As a result, only the reception signal 7 of the selected antenna is input to the antenna signal synthesis unit 53, and the reception signal synthesized by the antenna signal synthesis unit 53 among the antennas 51 _{1 to} 51 n is output. Hereinafter, a method of obtaining the antenna weight 811c in this way and combining the weights among the antennas 51 _{1 to} 51n is referred to as a “selective combining method”. According to such a weight control unit 811, there is an advantage that it can be realized with a simple configuration.

As shown in FIG. 9B, the antenna weight control section 812 includes a weight holding section 812a. The weight holding unit 812a holds a weight having a constant value. The antenna weight control unit 812 determines the weight of a constant value held in the weight holding unit 812a as the antenna weight 812b that multiplies the antennas 51 _{1 to} 51n. Therefore, the antenna weights by which the reception signals 7 of the antennas 51 _{1 to} 51 n are multiplied are all equal.

The antenna weight controller 812 has a fixed value of the antenna weight 81 determined by the antenna weight multiplier 52f.
Enter 2b. Then, the reception signal 7 multiplied by the antenna weight 812b having a constant value by the antenna weight multiplication unit 52f is input to the antenna signal synthesis unit 53, and the reception signal 7 is synthesized by the antenna signal synthesis unit 53 between the antennas 51 _{1 to} 51n. The signal 7 is output. Hereinafter, the antenna weight 812b is obtained in this manner, and the antennas 51 _{1 to} 51n
The method of combining the weights between the two is called "equal gain combining method". According to such a weight control unit 812, there are the following merits. Even if the received signal 7 does not have the maximum power, there is a signal having a large signal power to noise power ratio. Therefore, by multiplying the reception signals 7 of all the antennas 51 _{1 to} 51n by the same antenna weight 812b and combining them,
The signal power to noise power ratio can be further increased.

As shown in FIG. 9C, the antenna weight controller 813 includes a signal power detector 813a. Signal power detector 813a includes a plurality of antennas ₅₁ 1 _~51n
Detects the power of the received signal 7 received by. The signal power detection unit 813a detects, as the power of the received signal 7, the power of the received signal 7 itself, the power of the signal obtained by removing the influence of noise or the like from the received signal 7, and the like. The antenna weight controller 813
Each antenna ₅₁ to the signal power detector 813a detects 1
A weight proportional to the power of 51n is assigned to each of the antennas 51 ₁ ...
The antenna weight 813b to be multiplied by 51n is determined.

[0108] antenna weight controller 813, the antenna weight multiplying unit 52f of the respective antennas ₅₁ 1 _~51n, inputs the antenna weights 813b proportionate to the power of the received signal 7 of the antenna ₅₁ 1 _~51n. Then, the reception signal 7 multiplied by the antenna weight 813b proportional to the power of the reception signal 7 by the antenna weight multiplication unit 52f is input to the antenna signal combining unit 53, and the antenna signal combining unit 53 causes the antennas 51 _{1 to} 51n to be connected. The reception signal 7 combined in step S1 is output. Hereinafter, the method of obtaining the antenna weights in this way and synthesizing the received signals 7 among the antennas 51 _{1 to} 51n is referred to as a “maximum ratio synthesizing method”.

According to such a weight control unit 813, there are the following merits. The received signals 7 having power close to the noise power present in the received signals 7 are transmitted to the antennas 51 _{1 to} 5 _1.
The influence on the reception signal 7 after being combined for 1n is reduced, and the reception signal 7 with high power is transmitted to the antennas 51 _{1 to} 5 _1.
It is possible to increase the influence on the reception signal 7 after being combined for 1n. As a result, the signal power to noise power ratio can be further increased.

As in the case of using the antenna weight control unit 811, which uses the selective combining method, or the antenna weight control unit 813, which uses MRC, as the antenna weight control unit 81,
The antenna weight controller 81 may detect the information about the received signal 7 such as the power of the received signal 7 and determine the antenna weight. Information on the received signal 7 necessary for determining the antenna weight in this way is hereinafter referred to as "antenna weight information". The received signal 7 is included in the antenna weight information.
Power itself, the power of the received signal 7 after removing the influence of noise, etc. and the guard interval, the signal power to noise power ratio (SNR), the signal power to interference power ratio (SIR: Signal)
to Interference Power Ratio, CIR: Carrier to Interference Powe
r Ratio) etc.

As shown in FIG. 7, in the receiving device 5, the antenna weight controller 81 has the guard interval remover 52.
Antenna weight information is obtained from the received signal 7 after the guard interval is removed by b and before the time-frequency conversion processing is performed by the time-frequency conversion unit 52c. According to this, the antenna weight controller 81, by the time frequency converting unit 52c, from one reception signal 7 before being separated into received signal 7 on each sub-carrier antenna weight information for each antenna 51 ₁ ~51n Just get it. Therefore, the antenna weight controller 81 can simplify the process. It should be noted that the antenna weight control unit 81 separates the antenna weight information from the received signal 7 that has been separated into the received signal 7 for each subcarrier by the time frequency conversion unit 52c and has not been multiplied by the spreading code by the spreading code multiplication unit 52f. You may get it.

Further, as in the receiving apparatus 205 shown in FIG. 10, the antenna weight control unit 81 has the spreading code multiplication unit 52e.
The antenna weight information may be acquired from the received signal 7 after being multiplied by the spread code and before being multiplied by the antenna weight multiplication unit 52f. The receiving device 205 is substantially the same as the receiving device 5 shown in FIG. 7 except that the position where the weight control unit 81 acquires information about the received signal 7 is different. Therefore, in FIG. 10, the same reference numerals as those of the receiving device 5 are given and the description thereof is omitted.

In receiving apparatus 205, antenna weight control section 81 is able to obtain antenna weight information from received signal 7 after being multiplied by the spreading code and the influence of the spreading code being multiplied in transmitting apparatus 4 is removed. When the antenna weight control unit 81 wants to determine the antenna weight based on the antenna weight information after removing the influence of multiplication of the spreading code in the transmission device 4, the antenna from the received signal 7 before the multiplication code is multiplied. Once the weight information is acquired, it becomes necessary to perform the process of obtaining the antenna weight information after the multiplication of the spread code based on the antenna weight information. However, according to the receiving device 205, such a situation does not occur, and the processing performed by the antenna weight control unit 81 can be simplified.

Next, the method by which subcarrier weight control section 82 determines subcarrier weights will be explained using FIG. The subcarrier weight control unit 82 includes an orthogonal restoration combining method (hereinafter referred to as “ORC”), a maximum ratio combining method (Maximum Ratio Combining).
Hereinafter referred to as "MRC"), equal gain combining method (Equal GainC)
The sub-carrier weights are determined using methods such as combining (hereinafter referred to as “EGC”), minimum mean square error combining (hereinafter referred to as “MMSEC”), and the like.

The ORC, as shown in FIG. 11A, represents the reciprocal of the propagation path fluctuation value 9 of the received signal 7 for each subcarrier,
This is a method of determining the subcarrier weight 821c by which the received signal 7 of the subcarrier is multiplied. The propagation path fluctuation value is the power of the reception signal 7 after the transmission signal 6 transmitted by the transmission device 4 propagates through the propagation path between the transmission device 4 and the reception device 5 and undergoes phase fluctuation and amplitude fluctuation. Value of. According to the ORC, the propagation path fluctuation value 9 of the received signal 7 after the subcarrier weight multiplication becomes constant, and the plurality of information channels # 1 to #n
Has the advantage that the spreading codes of are orthogonal to each other.

As shown in FIG. 11B, the MRC has a subcarrier weight 8 for multiplying the received signal 7 of the subcarrier by the propagation path fluctuation value 9 of the received signal 7 for each subcarrier.
22b. According to MRC, SNR
Subcarriers with small S are multiplied by small subcarrier weights, and subcarriers with a large SNR are multiplied by large subcarrier weights. Therefore, there is an advantage that the SNR of the information symbol after combining the received signals 7 for each subcarrier can be maximized.

As shown in FIG. 11C, the EGC sets a constant value equal to the received signal 7 for every subcarrier to the subcarrier weight 823b regardless of the channel fluctuation value 9.
Is the way to decide. According to EGC, the received signal 7 for every subcarrier is multiplied by an equal weight. Therefore, it is possible to improve the signal power to noise power ratio of the information symbols after combining the received signals 7 for each subcarrier and to make the spreading codes of the plurality of information channels # 1 to #n orthogonal to each other. There is an advantage that you can.

As shown in FIG. 11 (d), the MSSEC multiplies the received signal 7 by the spread code, synthesizes the spread signal over the spread code period, and despreads the received signal 7 and the actual transmitted signal. This is a method of determining the subcarrier weight 824d so that the mean square error with the transmission signal 6 transmitted by the device 4 is minimized. According to MMSEC, the subcarrier weight 824d can be calculated according to the situation of the propagation path which changes every moment. Therefore, the state of the propagation path can be taken into consideration, the SNR of the information symbol after combining the received signal 7 for each subcarrier can be improved, and the spreading codes of the plurality of information channels # 1 to #n can be improved. Have the advantage that they can be orthogonal to each other.

A specific subcarrier weight controller 82 for executing such a method of determining a subcarrier weight is, for example, the subcarrier weight controller 82 shown in FIG.
There are 1 to 828. As shown in FIG. 12A, the subcarrier weight controller 821 includes a channel fluctuation value detector 821.
a and a reciprocal calculation unit 821b. The channel fluctuation value detection unit 821a detects the channel fluctuation value 9 from the received signal 7. The reciprocal calculation unit 821b includes a propagation path fluctuation value detection unit 82.
The reciprocal of the propagation path fluctuation value 9 detected by 1a is calculated, and the reciprocal of the calculated propagation path fluctuation value 9 is determined as the subcarrier weight 821c. According to such a subcarrier weight controller 821, the subcarrier weight 821c can be determined using the ORC.

As shown in FIG. 12B, the subcarrier weight controller 822 includes a channel fluctuation value detector 822a. The propagation path fluctuation value detection unit 822a detects the propagation path fluctuation value 9 from the received signal 7, and determines the detected propagation path fluctuation value 9 as the subcarrier weight 822b as it is. According to such a subcarrier weight controller 822, the subcarrier weight 822b can be determined using MRC.

As shown in FIG. 12C, the subcarrier weight control section 823 includes a weight holding section 823a. The weight holding unit 823a holds a weight having a constant value. The subcarrier weight control unit 823 acquires a weight having a constant value from the weight holding unit 823a, and determines the weight having the constant value as a subcarrier weight 823b equal to the received signal 7 for all subcarriers. According to such a subcarrier weight controller 823, the subcarrier weight 823b can be determined using EGC.

The subcarrier weight controller 824 shown in FIG. 11D includes an error estimator 824a, a reference symbol holder 824b, and a weight calculator 824c. The reference symbol holding unit 824b holds the reference symbol. The reference symbol is a symbol whose amplitude and phase are known in the transmitter 4 and the receiver 5. Here, as the reference symbol, the same symbol as the pilot symbol to be transmitted by the transmission device 4 is used. The error estimation unit 824a acquires the despread pilot symbol 72 included in the received signal 7 which is transmitted by the transmission device 4 and actually received by the reception device 5. The error estimation unit 824a acquires the reference symbol from the reference symbol holding unit 824b.
Then, the error estimation unit 824a determines that the pilot symbol 7
2 and the phase, amplitude, etc. of the reference symbol, and the actually received despread pilot symbol 72 and the transmitter 4
Determine the error from the pilot symbol transmitted by.

Error estimating section 824a estimates that the error between the obtained despread pilot symbol 72 and the pilot symbol transmitted by transmitter 4 is the error between despread received signal 7 and transmitted signal 6. To do. Error estimation unit 824a
Inputs the estimated value of the error between the reception signal 7 and the transmission signal 6 after despreading to the weight calculation unit 824c. Weight calculator 82
4c calculates the mean square error from the estimated value of the error between the reception signal 7 and the transmission signal 6 after despreading, and calculates the subcarrier weight 824d that minimizes the error. When the received signal 7 is first received, the weight calculation unit 824c does not have the despread pilot symbol 72 for estimating the error, and thus sets a preset initial value as the subcarrier weight.

Such subcarrier weight controller 824
According to MMSEC, subcarrier weights 824
d can be obtained. Further, by using the received pilot symbol 72 and the reference symbol, the error between the despread reception signal 7 and the transmission signal 6 is obtained in consideration of the actual state of the propagation path, and the optimum subcarrier weight 824 is obtained.
d can be obtained.

The subcarrier weight controller 825 shown in FIG. 12D is an error estimator 825a and a bit string holder 8
25b, a reference symbol generation unit 825c, and a weight calculation unit 825d. The bit string holding unit 825b holds a bit string that is the basis of a reference symbol whose amplitude and phase are known in the transmitter 4 and the receiver 5. The bit string holding unit 825b holds the bit string that is the basis of the pilot symbol to be transmitted by the transmission device 4. The reference symbol generation unit 825c includes a bit string holding unit 8
A bit string is acquired from 25b, and the bit string is modulated to generate a reference symbol. That is, the reference symbol generator 8
25c modulates the bit string to allow the transmitter 4
Generate the same reference symbols as the pilot symbols that are to be transmitted by the.

The error estimating section 825a is the same as in FIG. 11 except that the reference symbol is obtained from the reference symbol generating section 825c.
This is substantially the same as the error estimation unit 824a shown in (d). The weight calculator 825d is substantially the same as the weight calculator 824c shown in FIG. According to such a subcarrier weight controller 825, the subcarrier weight 825e can be obtained using MMSEC. Further, by using the received pilot symbol 72 and the generated reference symbol, the error between the despread reception signal 7 and the transmission signal 6 is obtained in consideration of the actual propagation path condition, and the optimum subcarrier is obtained. The weight 825e can be obtained.

The subcarrier weight controller 826 shown in FIG. 12 (e) includes a channel estimator 826a, a noise power estimator 826b, a code multiplex number estimator 826c, and a weight calculator 826d. Channel estimation unit 826a, noise power estimation unit 826b, code multiplex number estimation unit 826c
Holds the same symbols as pilot symbols that the transmitter 4 is supposed to transmit as reference symbols. The channel estimation unit 826a, the noise power estimation unit 826b, and the code multiplex number estimation unit 826c may hold the same signal as the pilot signal to be transmitted by the transmission device 4, as a reference signal.

Channel estimating section 826a acquires pilot symbol 72 included in received signal 7 which transmitting apparatus 4 transmitted and receiving apparatus 5 actually received. The channel estimation unit 826a compares the acquired pilot symbol 72 and the reference symbol with each other in phase, amplitude, etc., and obtains the propagation path fluctuation amount of the pilot symbol 72. Then, channel estimation section 826a performs channel estimation using the channel fluctuation amount of pilot symbol 72, and obtains a channel estimation value. The channel estimation unit 826a may compare the pilot signal included in the received signal 7 with the reference signal to obtain the channel estimation value.

Noise power estimating section 826b acquires pilot symbol 72 included in received signal 7 which transmitting apparatus 4 transmitted and receiving apparatus 5 actually received. The noise power estimation unit 826b compares the acquired pilot symbol 72 with the reference symbol to obtain the amount of variance of the pilot symbol 72. Then, the noise power estimation unit 826b estimates the noise power per subcarrier of the received signal 7 by using the obtained variance amount. The noise power estimation unit 826b may compare the pilot signal included in the received signal 7 with the reference signal to obtain the amount of dispersion of the pilot signal.

The code multiplexing number estimation unit 826c acquires the pilot symbol 72 and the information symbol 71 included in the received signal 7 transmitted by the transmitter 4 and actually received by the receiver 5. The code multiplexing number estimation unit 826c calculates the ratio between the power of the pilot symbol 72 and the power of the information symbol 71. Then, the code multiplex number estimation unit 826c
The code multiplexing number is estimated from the calculated ratio of the power of the pilot symbol 72 and the power of the information symbol 71. Here, the spreading codes are generated by the number corresponding to each of the information channels # 1 to #n. Therefore, the code multiplexing number corresponds to the number of information channels # 1 to #n to be code-multiplexed. still,
The code multiplexing number estimation unit 826c may estimate the code multiplexing number based on the pilot signal and the information signal included in the received signal 7.

Channel estimation section 826a, noise power estimation section 826b, and code multiplexing number estimation section 826c respectively input the channel estimation value, noise power estimation value, and code multiplexing number estimation value to weight calculation section 826d. Weight calculator 826
For d, the subcarrier weight 826e is calculated by substituting the channel estimation value of the received signal 7, the estimation value of the noise power, and the estimation value of the code multiplexing number into the equation (1) shown below.

Equation (1) is obtained by multiplying the received signal 7 by the spread code.
And the received signal 7 after despreading and the actual transmitter
4 has the minimum mean squared error with the transmitted signal 6 transmitted by
In the formula for calculating the subcarrier weight 826e,
is there. In equation (1), w _mIs the subcarrier weight, h
_mIs the channel estimate, N is the noise power, C_muxIs a code
Means a multiple. m represents the subcarrier number. still,
For example, the calculation method of the subcarrier weight using the equation (1) is
For example, `` Design and Performance of Multicarrier
CDMA System in Frequency-Selective Rayleigh F
ading Channels (S. Hara et al., IEEE TRANSCAT
IONS ON VEHICULAR TSCHNOLOGY, pp. 1584-1595, VO
L. 48, NO. 5, September 1999) ”.

W _m = h _m / (C _mux | h _m | ² + N) (1) According to such a subcarrier weight control unit 824, M
Subcarrier weight 826e can be determined using MSEC. In addition, the subcarrier weight control section 824 determines that the actually received pilot symbol 72 or information symbol 7 is received.
By using 1 and the reference symbol, the channel estimation value, noise power, and code multiplexing number can be estimated in consideration of the actual state of the propagation path, and the optimum subcarrier weight 826e can be obtained.

The subcarrier weight controller 827 shown in FIG. 12 (f) includes an error estimator 827a, a reference symbol holder 827b, and a weight updater 827c. The error estimation unit 827a and the reference symbol holding unit 827b are the same as those in FIG.
The error estimation unit 824a and the reference symbol holding unit 824b shown in 1 (d) are substantially the same.

Weight updating section 827c substitutes the estimated value of the error between despread reception signal 7 and transmission signal 6 into the adaptive algorithm. The weight updating unit 827c determines the subcarrier weight 827d that is sequentially updated by executing the adaptive algorithm. The adaptive algorithm is based on the estimated value of the error between the despread reception signal 7 and the transmission signal 6, and gradually updates the subcarrier weight 827d so that the mean square error of the error becomes minimum. It is an algorithm to do. Examples of adaptive algorithms include LMS (Least Mean Square) and RLS (Recursi).
ve Least Squares) can be used. The adaptive algorithm is, for example, "Orthogonal multi-carr
ier techniques applied to direct sequence CD
MA systems (A Chouly et. Al., 1993 IEEE Glob
al Telecommunications Conference).

When the received signal 7 is first received, the weight updating section 827c does not have a despread pilot symbol for estimating an error, and therefore the preset initial value is set to the subcarrier weight 827d. And According to such a subcarrier weight controller 824, the subcarrier weight 827d can be obtained using MMSEC.
Further, the weight updating unit 827c uses the received pilot symbol 72 and the reference symbol to obtain the error between the despread reception signal 7 and the transmission signal 6 in consideration of the actual state of the propagation path, Optimal subcarrier weight 827d
Can be asked. Furthermore, the weight updating unit 827c
By using the adaptive algorithm, the subcarrier weight 827d can be gradually updated so that the mean square error between the despread reception signal 7 and the transmission signal 6 is minimized.

The subcarrier weight controller 828 shown in FIG. 12 (g) includes an error estimator 828a and a bit string holder 8
28b, a reference symbol generation unit 828c, and a weight update unit 828d. The error estimation unit 828a, the bit string holding unit 828b, and the reference symbol generation unit 828c are as shown in FIG.
The error estimation unit 825a and the bit string holding unit 8 shown in (d)
25b and the reference symbol generator 825c. The weight updating unit 828d is substantially the same as the weight updating unit 827c shown in FIG.

Such a subcarrier weight controller 828
According to, subcarrier weights 828 using MMSEC
e can be obtained. In addition, the subcarrier weight controller 828 controls the pilot symbol 7 received by the receiver 5.
2 and the generated reference symbol, the error between the despread reception signal 7 and the transmission signal 6 is obtained in consideration of the actual propagation path situation, and the optimum subcarrier weight 82
8e can be obtained. Further, the subcarrier weight controller 828 uses an adaptive algorithm to
The subcarrier weight 827d can be gradually updated so that the mean square error between the reception signal 7 and the transmission signal 6 after despreading becomes the minimum.

Incidentally, FIG. 11 (d), FIG. 12 (d), and FIG.
Error estimation units 824a, 825a, 827 shown in (e)
a and 828a refer to the despread pilot symbol 72 and the information symbol 71, that is, the despread received signal 7 itself when estimating the error between the despread received signal 7 and the transmitted signal 6. It is also possible to obtain an error with respect to the signal and estimate that the error is an error between the reception signal 7 and the transmission signal 6 after despreading. According to this, the weight calculation units 824c, 82
5d and the weight update units 827c and 828d can use the estimated value of the error between the actually received despread reception signal 7 and the transmission signal 6, and a more appropriate subcarrier weight 8
24d, 825e, 827d, 828e can be obtained. In that case, the error estimation units 824a, 825a, 8
27a and 828a are provided with a decision feedback unit for acquiring the reference signal. The decision feedback unit acquires the reception signal 7 that has been combined by the symbol combining unit 55 over the spreading code period. The decision feedback section decides what the transmission signal 6 was based on the received signal 7, and inputs it to the error estimation sections 824a, 825a, 827a, 828a.
Then, the error estimation units 824a, 825a, 827a, 8
28a uses the transmission signal 6 determined by the determination feedback unit as a reference signal.

As the subcarrier weight controller 82,
Subcarrier weight controller 821 using ORC, MRC
As in the case of using the subcarrier weight control unit 822 that uses the subcarrier weight control unit 822 and the subcarrier weight control units 824 to 828 that use the MMSEC, the subcarrier weight control unit 82 controls the channel fluctuation value 9 of the received signal 7, the pilot symbol 71, and the pilot. In some cases, information about the received signal 7, such as the phase and amplitude of the signal, the information symbol 71, and the power of the information signal, is detected to obtain the subcarrier weight. Information on the received signal 7 necessary for determining the subcarrier weight in this way is hereinafter referred to as "subcarrier weight information". After removing the propagation path fluctuation value 9 of the received signal 7, the phase and amplitude of the pilot symbol 72 and the pilot signal, the power itself of the information symbol 71 and the information signal, the influence of noise, and the guard interval, the subcarrier weight information is obtained. Of the received signal 7, the phase and amplitude of the pilot symbol 72 and the pilot signal, the power of the information symbol 71 and the information signal, and the like.

As shown in FIG. 7, in the receiving apparatus 5, the subcarrier weight control unit 82 is arranged after the reception signal 7 multiplied by the antenna weight is combined by the antenna signal combining unit 53 between the antennas. The subcarrier weight multiplication unit 54 acquires subcarrier weight information from the received signal 7 before being multiplied by the subcarrier weight. According to this, the subcarrier weight control unit 82 may acquire the subcarrier weight information from the combination of the received signals 7 among the plurality of antennas by the antenna signal combination unit 53. Therefore, the sub-carrier weight controller 82, the signal processing unit ₅₂ of the plurality of antennas ₅₁ 1 _~51n 1 _~52
Since it is not necessary to acquire the subcarrier weight information from n, the processing can be simplified.

Further, subcarrier weight control section 82 can obtain subcarrier weight information from received signal 7 after being multiplied by antenna weights and combined among a plurality of antennas. Therefore, the subcarrier weight controller 82
Can calculate the subcarrier weight in consideration of the influence on the received signal 7 due to the multiplication by the antenna weight and the influence on the received signal 7 due to the combination between the antennas. In addition, in this case, the subcarrier weight control unit 82 obtains the subcarrier weight information from the received signal 7 after being multiplied by the spreading code, so that the influence of the spreading code multiplied by the transmitting device 4 is removed. A more appropriate subcarrier weight can be obtained by using the information of the received signal 7 after being stripped.

The subcarrier weight control unit 82 calculates from the received signal 7 after the antenna weight is multiplied by the antenna weight multiplication unit 52f and before the received signal is synthesized between the antennas by the antenna signal synthesis unit 53, Subcarrier weight information may be acquired. According to this, the subcarrier weight control unit 82 can obtain the subcarrier weight information from the received signal 7 after being multiplied by the antenna weight, and the received signal 7 by being multiplied by the antenna weight can be obtained.
The subcarrier weight can be obtained in consideration of the influence on the subcarrier weight. Further, in this case, the subcarrier weight controller 82
Is based on the subcarrier weight information acquired from the reception signal 7 after the antenna weight multiplication unit 52f multiplies the antenna weights and before the reception signals are combined between the antennas by the antenna signal combination unit 53, Subcarrier weight information after combining between antennas can be estimated.
Then, the subcarrier weight controller 82 can also obtain the subcarrier weight from the estimated information.

Further, in these cases, the subcarrier weight controller 82 obtains the subcarrier weight information from the received signal 7 after being multiplied by the spread code, so that the transmitting device 4
A more appropriate subcarrier weight can be obtained by using the information of the received signal 7 after the influence of the spreading code multiplied in is removed.

Further, the subcarrier weight controller 82 receives from the received signal 7 between the time frequency converter 52c and the spread code multiplier 52e and receives between the spread code multiplier 52e and the antenna weight multiplier 52f. Subcarrier weight information may be obtained from the signal 7.

As the subcarrier weight controller 82,
The subcarrier weight control units 824, 825, 827, 82 shown in FIGS. 11D, 13D, 13F, and 8G.
When 8 is used, it is necessary to obtain the subcarrier weight using the pilot symbol 72 after despreading and the received signal 7 after despreading. Therefore, in these cases, FIG.
It is preferable that the subcarrier weight control unit 82 obtains the subcarrier weight information from the received signal 7 that has been despread by the symbol combining unit 55, as in the receiving apparatus 205 shown in FIG. According to this, the subcarrier weight control unit 82 can use the acquired subcarrier weight information as it is, and thus the processing can be simplified.

As the subcarrier weight controller 82,
When the subcarrier weight control unit 826 shown in FIG. 12E is used, for example, as shown in FIG. 7, subcarrier weight information can be acquired from the received signal 7 in a state of being separated for each subcarrier. preferable. Then, subcarrier weight control section 82 preferably determines the subcarrier weight based on received signal 7 for each subcarrier.
According to this, the channel estimation unit 826a, the noise power estimation unit 826b, and the code multiplexing number estimation unit 826c respectively
The channel estimation value, noise power estimation value, and code multiplexing number estimation value can be estimated for each subcarrier.

Further, as described above, when the antenna weight controller 81 and the subcarrier weight controller 82 acquire the antenna weight information and the subcarrier weight information from different positions, respectively, the antenna weight controller 81 and the subcarrier weight information are obtained. Each of the carrier weight control units 82 can acquire information at the optimum position for determining the antenna weight and the subcarrier weight, and can perform highly accurate control.

On the other hand, the weight control unit 8 obtains the information of the common received signal 7 as the antenna weight information and the subcarrier weight information from one place, and the antenna weight control unit 81 and the subcarrier weight control unit 82 share the common information. Information may be used. In this case, the weight controller 8 can acquire the antenna weight information and the subcarrier weight information at one time.
Therefore, the weight control unit 8 can simplify the processing. or,
The configuration of the receiving device 5 is also simplified.

The receiving devices 5 and 20 shown in FIG. 7 and FIG.
5, the antenna weight multiplication unit 52f causes the antenna 51
The reception signal 7 for each _{1 to} 51n is multiplied by the antenna weight, and the antenna signal combining unit 53 performs the space diversity combining for combining the reception signal 7 multiplied by the antenna weight between the antennas, and then the subcarrier weight multiplying unit 54, the received signal 7 for each subcarrier multiplied by the spread code is multiplied by the subcarrier weight, and the symbol combining unit 55 combines the received signal 7 multiplied by the subcarrier weight over the spread code period. In the case of spreading, the subcarrier weight controller 82 maintains the state of the reception signal 7 multiplied by the antenna weight or multiplies the antenna weight based on the antenna weight which is multiplied by the reception signal 7 first. It is determined whether the state of the received signal 7 should be adjusted again. Then, the subcarrier weight control unit 82 preferably adjusts the subcarrier weight based on the determination result. Further, in this case, the antenna weight control unit 81 determines the antenna weight using the equal gain combining method, and the subcarrier weight control unit 82 uses the MMSE.
It is preferred to use either C or EGC to determine the subcarrier weights.

(Communication Method) Next, a communication method will be described. First, a case of transmitting a transmission signal using the transmission device 4 shown in FIG. 2 will be described. As shown in FIG. 13, the transmission device 4 generates information symbols to be transmitted on each of the information channels # 1 to #n (S101). Transmitter 4
Performs error correction coding on the generated information symbol (S102). The transmission device 4 performs data modulation processing on the information symbols that have been subjected to error correction coding (S103). The transmitter 4 performs serial-parallel conversion on the information symbols subjected to the data modulation processing, and divides the information symbols into a plurality of information symbols (S104).

Next, the transmitting device 4 makes the number of the plurality of information symbols, which are serial-parallel converted and divided, equal to the spreading code period of the spreading code corresponding to the information channels # 1 to #n for transmitting the information symbols. Only is copied (S105). The transmitter 4 generates a spreading code corresponding to each information channel assigned to each information channel. Then, the transmission device 4 multiplies the duplicated information symbol by the spreading code corresponding to the information channels # 1 to #n for transmitting the information symbol, to obtain an information signal (S106).

Then, transmitting apparatus 4 inserts a pilot signal into the information signal (S107). The transmitter 4 combines the information signals of the respective information channels # 1 to #n and the pilot signal, and code-multiplexes them (S108). Then, the transmitter 4
Spreads the code-multiplexed information signal to a plurality of subcarriers having different frequencies for transmitting the information signal (S1
09). Specifically, the transmitter 4 frequency-time converts the information signal, allocates the information signal to a plurality of subcarriers having different frequencies, and generates a multicarrier CDMA signal. The transmission device 4 inserts a guard interval for each information signal spread over a plurality of subcarriers (S
110). Then, the transmission device 4 transmits the multicarrier CDMA signal with the guard interval inserted as the transmission signal 6 to the reception device 5 (S111).

Next, the case of receiving a received signal using the receiving apparatus 5 shown in FIG. 7 will be described. As shown in FIG. 14, a plurality of antennas 51 _{1 to} 51 n of the receiving device 5 are provided.
However, the transmitter 4 causes the plurality of information channels # 1 to #n to be transmitted.
A multi-carrier CDMA signal transmitted by a plurality of subcarriers having different frequencies, which is a signal obtained by multiplying a plurality of information symbols transmitted in step S1 by a spreading code for each information channel, is received (S201). .. Receiving apparatus 5, for each reception signal 7 by the antenna ₅₁ 1 _~51n received, to establish synchronization of the symbol timing (S20
2). The receiving device 5 removes the guard interval inserted in the received signal 7 (S203).

Next, the receiving device 5 time-frequency converts the received signal 7, and separates the received signal 7 spread over a plurality of subcarriers having different frequencies into the received signal 7 for each subcarrier (S204). The receiving device 5 generates a spreading code similar to the spreading code multiplied by the received signal 7. Then, the receiving device 5, the reception signal 7 received by the plurality of antennas ₅₁ 1 _~51n, multiplies the spreading code information channel corresponding to the received signal 7 (S205).

Next, the receiving apparatus 5 determines the antenna weights, and the determined antenna weights are used as the antennas 51 _{1 to} 51n.
Each received signal 7 is multiplied (S206). The receiver 5 combines the reception signals 7 among the antennas ₅₁ 1 _~51n (S207). In this way, spatial diversity combining is performed. Next, the reception device 5 determines the subcarrier weight, and multiplies the received signal for each subcarrier by the determined subcarrier weight (S2).
08). Then, the receiving device 5 synthesizes the received signal 7 over the spread code period (S209). In this way
Despreading occurs. As a result, the information symbol before being multiplied by the spreading code in the transmitter 4 is restored.

Next, the receiving device 5 parallel-serial converts the information symbols that have been combined and restored over the spreading code period (S210). The reception device 5 performs data demodulation processing on the parallel-serial converted information symbols (S211).
The receiving device 5 performs error correction decoding processing on the information symbols that have been subjected to data demodulation processing (S212). Finally, the receiving device 5 restores the information symbol that has been subjected to the error correction decoding processing to a state in which it can be output to an output device such as a display or a speaker, and outputs it to the output device (S21).
3).

(Effects) According to the communication system 1, the transmitters 4, 204, 304, the receivers 5, 205 and the communication method as described above, the following effects can be obtained. In the receiving devices 5 and 205, the plurality of antennas 51 _{1 to} 51 n are included.
Is a signal obtained by multiplying a plurality of information symbols by spreading codes for each of information channels # 1 to #n, and receives a transmission signal 6 transmitted by a plurality of subcarriers having different frequencies. The spread code generator 52d generates a spread code of the information channel corresponding to the received signal 7. The spread code multiplication unit 52e multiplies the received signal 7 by the spread code. The weight control unit 8 adjusts the antenna weight and the subcarrier weight so that the spread codes of the plurality of information channels # 1 to #n are orthogonal to each other. Then, the antenna weight multiplication unit 52f and the subcarrier weight multiplication unit 54 multiply the received signal 7 by the antenna weight and the subcarrier weight adjusted by the weight control unit 8. Finally, the antenna signal synthesizer 53
And the symbol synthesizing unit 55 synthesizes the received signal 7 multiplied by the antenna weight and the subcarrier weight, between the antennas and over the spreading code period of the spreading code.

Therefore, the received signal 7 is multiplied by the weight controller 8 with the antenna weight and the subcarrier weight adjusted so that the spread codes of the plurality of information channels # 1 to #n are orthogonal to each other. Therefore, the spread codes of the information channels # 1 to #n multiplied by the received signal 7 are orthogonal to each other. As a result, the information symbols obtained in the receiving devices 5 and 205 have reduced the influence of interference between the information channels # 1 to #n, which is caused by the collapse of the orthogonality between the spread codes. In this way, the receiving devices 5, 2
No. 05 can appropriately apply the space diversity combination to the multi-carrier CDMA transmission system. As a result, the receiving devices 5 and 205 can increase the signal power to noise power ratio of the received signal 7 for each subcarrier, and can improve the signal transmission characteristics.

The weight controller 8 comprises an antenna weight controller 81 and a subcarrier weight controller 82. Then, the weight control unit 8 adjusts the antenna weight and the subcarrier weight to individually obtain the antenna weight and the subcarrier weight. Then, the receiving device 5 has an antenna weight multiplication unit 5 that multiplies the received signal 7 for each antenna by the antenna weight.
2f and a subcarrier weight multiplication unit 54 that multiplies the received signal 7 for each subcarrier by the subcarrier weight.
Further, an antenna signal combining unit 53 that combines the received signal 7 between the antennas and a symbol combining unit 55 that combines the received signal 7 over the spread code period are provided.

Therefore, the receiving apparatus 5 obtains the antenna weight, multiplies the received signal 7 for each antenna by the antenna weight, synthesizes the received signal 7 between the antennas, obtains the subcarrier weight, and obtains each subcarrier. It is possible to individually perform the processing of multiplying the received signal 7 of (1) by the subcarrier weight and combining the received signal 7 over the spreading code period. As a result, the antenna weight controller 81 determines that the received signal 7
The antenna weight can be determined in consideration of the process of multiplying by with the subcarrier weight and combining the results over the spreading code period. On the other hand, the subcarrier weight control unit 82 can determine the subcarrier weight in consideration of the process of multiplying the received signal 7 by the antenna weight and combining the received signals 7 over the antennas 51 ₁ to 51 n.

In the subcarrier weight multiplication unit 54, the antenna weight multiplication unit 52f multiplies the reception signal 7 for each antenna by the antenna weight, and the antenna signal combination unit 53 combines the reception signal 7 between the antennas. After that, the received signal 7 for each subcarrier multiplied by the spread code is multiplied by the subcarrier weight. Then, the symbol combining unit 55, after performing the space diversity combining,
Despreading is performed in which the received signal 7 multiplied by the subcarrier weight is combined over the spreading code period. Therefore, the subcarrier weight multiplying unit 54 and the symbol combining unit 55 individually multiply the received signals 7 of the plurality of antennas 51 _{1 to} 51n by the subcarrier weights, and combine the received signals 7 over the spread code period. There is no need to carry out processing. That is, the sub-carrier weight multipliers 54 and the symbol combining unit 55, the received signals are combined among a plurality of antennas ₅₁ 1 _~51n 7
, The process of multiplying the subcarrier weights collectively,
It is possible to perform processing for synthesizing the received signal 7 over the spread code period.

Further, according to the transmitters 4, 204, 304, the serial / parallel converters 41d, 241d divide the information symbols transmitted on the plurality of information channels # 1 to #n into a plurality of information symbols. Symbol duplication units 41f and 241f
, But information channels # 1 to # transmitting the information symbols
Information symbols are duplicated by the number equal to the spreading code period of the spreading code corresponding to n. The spread code generator 41e generates a spread code corresponding to the information channel. Spreading code multiplication units 41g, 241g, 341g multiply the duplicated information symbol by a spreading code to obtain an information signal. The frequency-time converter 43 spreads the information signal and the pilot signal on a plurality of subcarriers having different frequencies. Then, the guard interval insertion unit 44 inserts a guard interval for each information signal spread over a plurality of subcarriers. Therefore, the transmitting devices 4, 204, 304
Can simultaneously transmit a plurality of information signals of a plurality of information channels # 1 to #n by a plurality of subcarriers having different frequencies. Also, the transmitters 4, 204, 304
Can reduce the influence of interference of a plurality of information signals that arrive at the receiving device after being delayed due to the influence of multipath propagation. Therefore, the transmitters 4, 204, 304 are
The transmission characteristics can be improved.

Further, transmitting apparatuses 4, 204 and 304 are provided with pilot symbol inserting sections 41h, 241h and 341h, and insert pilot symbols into information symbols.
Therefore, the transmitters 4, 204, 304 can transmit the pilot symbols whose amplitude and phase are known in the receivers 5, 205 to the receivers 5, 205 together with the information symbols. Therefore, the receiving device compares the actually received pilot symbol with the pilot symbol to be transmitted from the transmitting device 4, 204, 304 whose amplitude and phase are known, to determine the propagation path of the pilot symbol. It is possible to obtain the variation amount and the error between the received despread pilot symbol and the transmitted pilot symbol. Then, the receiving apparatus can perform channel estimation using the channel fluctuation amount of the pilot symbol. Also, the receiving apparatus can estimate the error between the received signal and the transmitted signal after despreading using the error of the pilot symbol.

[Second Embodiment] Next, the second embodiment of the present invention will be described.
A communication system and a communication method according to the embodiment will be described. In the communication system according to the second embodiment,
As a receiving device, the receiving device 305 shown in FIG. 15 is provided.

(Receiver) As shown in FIG. 15, the receiver 305 includes a plurality of antennas 51 _{1 to} 51 n, a plurality of signal processors 352 _{1 to} 352 n, and a weight controller 308.
, Antenna signal symbol synthesis section 353, serial-parallel conversion section 56, data demodulation section 57, and error correction decoding section 58.
And an information symbol restoration unit 59. Signal processing unit 3
52 ₁ ~352n, the symbol timing synchronization unit 52a
A guard interval removal unit 52b, a time frequency conversion unit 52c, a spread code generation unit 52d, a plurality of spread code multiplication units 52e, and a plurality of collective weight multiplication units 352f.

A plurality of antennas 51 _{1 to} 51 n, a serial / parallel conversion unit 56, a data demodulation unit 57, and an error correction decoding unit 5
8, an information symbol restoration unit 59, a symbol timing synchronization unit 52a, a guard interval removal unit 52b,
A time frequency conversion unit 52c, a spread code generation unit 52d,
The spreading code multiplication unit 52e is substantially the same as the reception device 5 shown in FIG. Therefore, in FIG. 15, the same reference numerals are given and the description thereof is omitted.

After the plurality of antennas 51 _{1 to} 51 n receive the transmission signal 6, the spreading code multiplication unit 52 e receives the reception signal 7.
Until it is multiplied by the spreading code, the receiving device 5 shown in FIG.
Processing similar to is performed. The spreading code multiplication unit 52e multiplies the received signal 7 multiplied by the spreading code by the collective weight multiplication unit 352f.
To enter.

Weight control section 308 adjusts the antenna weights and subcarrier weights so that the spread codes of a plurality of information channels # 1 to #n are orthogonal to each other, so that received signal 7 for each subcarrier of each antenna is adjusted. A weight to be collectively multiplied (hereinafter, referred to as "collective weight") is determined. Weight control unit 3
08 is preferably such that the spreading codes of the plurality of information channels # 1 to #n are orthogonal to each other and the antenna weight and subcarrier weight are adjusted so that the signal power to noise power ratio (SNR) becomes large, Determine the collective weight. According to this, the receiving device 305 can also increase the signal power to noise power ratio of the received signal 7, and can further improve the signal transmission characteristics.

The weight control unit 308 adjusts the antenna weights using the selective combining method, the equal gain combining method, the maximum ratio combining method, etc., and adjusts the subcarrier weights using the ORC, MRC, EGC, MMSEC, etc. , Determine the collective weight. The weight control unit 308 is the antenna weight control unit 81 shown in FIG.
1 to 813, and the subcarrier weight control units 821 to 828 shown in FIG. 11D and FIG. Then, the weight control unit 308 adjusts the antenna weight and the subcarrier weight to directly determine the collective weight.

The weight control unit 408 shown in FIG. 16 may be used as the weight control unit for determining the collective weight. The weight control unit 408 includes an antenna weight control unit 481, a subcarrier weight control unit 482, and a collective weight control unit 483. The antenna weight controller 481 determines the antenna weight. The subcarrier weight controller 482 determines the subcarrier weight. The antenna weight controller 481
Antenna weights are determined using the above-described selective combining method, equal gain combining method, maximum ratio combining method, and the like. Further, as the antenna weight control unit 481, for example, the antenna weight control units 811 to 813 shown in FIG. 9 can be used. The subcarrier weight controller 482 uses the ORC, MRC, and E described above.
Subcarrier weights are determined using GC, MMSEC, etc. As the subcarrier weight control unit 482, for example,
The subcarrier weight control units 821 to 828 shown in FIG. 11D and FIG. 12 can be used. The antenna weight controller 481 and the subcarrier weight controller 482 input the determined antenna weight and subcarrier weight to the collective weight controller 483.

Collective weight control section 483 adjusts the antenna weight determined by antenna weight control section 481 and the subcarrier weight determined by subcarrier weight control section 482 to determine collective weight 484. In this way, the weight control unit 408 once individually obtains the antenna weight and the subcarrier weight, and then determines the collective weight 484 based on them.

The collective weight multiplication unit 352f is used by the weight control unit 3
08, 408 is a weight multiplication unit that collectively multiplies the received signal 7 for each subcarrier of each antenna 51 _{1 to} 51 n by the collective weight adjusted by 08.408. Collective weight multiplication unit 35
2f multiplies the reception signal 7 received by the antennas 51 _{1 to} 51n, which the signal processing units 352 _{1 to} 352n perform signal processing, by a collective weight. The collective weight multiplication unit 352f is provided for each of the plurality of subcarriers. Each collective weight multiplication unit 35
2f multiplies the received signal 7 for each subcarrier input from each spreading code multiplication unit 52e by the collective weight. The collective weight multiplying unit 352f of each of the signal processing units 352 _{1 to} 352n inputs the received signal 7 multiplied by the collective weight to the antenna signal symbol combining unit 353.

Antenna signal symbol synthesis section 353 receives signals 7 multiplied by the collective weight as antennas 51 _{1 to} 5 _1.
It is a synthesizing unit for synthesizing collectively for 1n and spread code periods. The antenna signal symbol synthesis unit 353 is a collective weight multiplication unit 352f of each of the signal processing units 352 _{1 to} 352n.
The received signal 7 input from the antennas 51 _{1 to} 51 n
And information channels # 1 to # corresponding to the received signal 7
The spread codes of n spread codes are collectively combined. As a result, diversity combining and despreading are collectively performed.

In the receiving device 305, the spread code multiplication unit 52
e is the received signal 7 for each subcarrier, and the received signal 7
After the spread codes of the information channels # 1 to #n corresponding to are multiplied, the collective weight multiplication unit 352f causes the antennas 51 ₁ to
The received signal 7 for each 51n subcarrier is collectively multiplied by the collective weight. Then, the antenna signal symbol combining unit 3
53 collectively combines the received signals 7 between the antennas 51 _{1 to} 51 n and over the spread code period. As a result of combining by the antenna signal symbol combining unit 353, the information symbol before being multiplied by the spreading code in the transmitting device is restored.

The received signal 7 synthesized by the antenna signal symbol synthesizer 353 is input to the serial / parallel converter 56. After that, the same processing as that of the receiving device 5 shown in FIG. 7 is performed, and the information symbol is output.

The weight control units 308 and 408 acquire antenna weight information and subcarrier weight information from the received signal 7 when the selective combining method, the maximum ratio combining method, ORC, MRC, MMSEC, etc. are used. Weight control units 308, 40
As shown in FIG. 15, 8 indicates antenna weight information from the received signal 7 after the spreading code is multiplied by the spreading code multiplication unit 52e and before the collective weight is multiplied by the collective weight multiplication unit 352f. And the subcarrier weight information are collectively acquired. According to this, the weight control unit 30
The processing performed by 8, 408 is simplified. Further, the weight control units 308 and 408 can acquire the antenna weight information and the subcarrier weight information from the received signal 7 after being multiplied by the spread code and the influence of the spread code being multiplied in the transmission device is removed. Therefore, the weight control units 308 and 408 can obtain an appropriate collective weight. The weight control unit 3
08 and 408 may acquire antenna weight information and subcarrier weight information from the received signal 7 between the time frequency conversion unit 52c and the spreading code multiplication unit 52e.

The weight control units 308 and 408 detect the received signal 7 after the guard interval is removed by the guard interval removal unit 52b and before the time-frequency conversion processing is performed by the time-frequency conversion unit 52c. You may acquire antenna weight information and subcarrier weight information. According to this, the weight control units 308 and 408
The antenna 5 receives the antenna weight information and the subcarrier weight information from one received signal 7 before being separated into the received signal 7 for each subcarrier by the time-frequency converter 52c.
It may be acquired for each of 1 _{1 to} 51n, and the weight control unit 308,
The processing performed by 408 can be simplified.

In addition, the weight control units 308 and 408 are configured as shown in FIG.
As in subcarrier weight control sections 824, 825, 827, 828 shown in (d), (d), (f), and (g) of FIG. 12, despread pilot symbols 72 and despread received signals 7 may be used to adjust the subcarrier weights to determine the collective weights. In these cases, the weight control units 308 and 408 have the antenna signal symbol combining unit 3
It is preferable to acquire the subcarrier weight information from the received signal 7 that has been despread by 53. According to this, the subcarrier weight control unit 82 can use the acquired subcarrier weight information as it is, and thus the processing can be simplified.

In addition, the weight control units 308 and 408 are configured as shown in FIG.
As in the subcarrier weight controller 826 shown in (e), the subcarrier weight may be adjusted to determine the collective weight. In this case, the weight control units 308 and 408 preferably acquire the subcarrier weight information from the received signal 7 separated for each subcarrier. According to this
The channel estimation unit 826a, the noise power estimation unit 826b, and the code multiplexing number estimation unit 826c can estimate the channel estimation value, the noise power estimation value, and the code multiplexing number estimation value for each subcarrier.

The weight control units 308 and 408 may acquire antenna weight information and subcarrier weight information from different positions. According to this, the weight control units 308, 40
8 can acquire information at an optimum position for determining the antenna weight and subcarrier, and can perform highly accurate control.

(Communication Method) Next, the case of receiving a received signal using the receiving apparatus 305 shown in FIG. 15 will be described. As shown in FIG. 17, the receiving device 305 performs step (S301) to step (S305). Steps (S301) to (S305) are substantially the same as steps (S201) to (S205) shown in FIG.

Next, the receiving apparatus 305 determines the collective weight, and collectively multiplies the received signal 7 for each subcarrier of the antennas 51 _{1 to} 51n by the determined collective weight (S).
306). The reception device 305 collectively combines the reception signal 7 multiplied by the collective weight over the antennas 51 _{1 to} 51 n and over the spreading code period. (S307). In this way, space diversity combining and despreading are performed collectively. As a result, the information symbol before being multiplied by the spreading code in the transmitting device is restored.

Next, as shown in FIG.
5 performs step (S308) -step (S311). Step (S308) to Step (S311)
Indicates steps (S210) to (S21) shown in FIG.
Substantially the same as 3).

(Effect) According to the communication system, the receiving device 305, and the communication method as described above, the following effects can be obtained. The weight control unit 308 adjusts the antenna weight and the subcarrier weight so that the spread codes of the plurality of information channels # 1 to #n are orthogonal to each other, and obtains the collective weight for collectively multiplying the received signals 7. Collective weight multiplication unit 3
52f multiplies the received signal 7 for each subcarrier of each antenna 51 _{1 to} 51n by the collective weight. The antenna signal symbol combining unit 353, a reception signal 7 obtained by multiplying the bulk weight, synthesized collectively over and spreading code period between antennas 51 ₁ ~51n.

Therefore, the weight controller 30 is applied to the received signal 7.
8 multiplies the collective weights adjusted so that the spreading codes of the plurality of information channels # 1 to #n are orthogonal to each other. Therefore, the spread codes of the information channels # 1 to #n multiplied by the received signal 7 are orthogonal to each other. As a result, the information symbol obtained in the receiving device 305 is
This reduces the influence of interference between the information channels # 1 to #n caused by the collapse of the orthogonality between the spread codes. In this way, the receiving device 305 has the multi-carrier C
Spatial diversity combining can be appropriately applied to the DMA transmission method. As a result, the receiving devices 5 and 205 can increase the signal power to noise power ratio of the received signal 7 for each subcarrier, and can improve the signal transmission characteristics.

Further, the receiving device 305 can collectively perform the processing for obtaining the collective weight, the processing for multiplying the collective weight, and the processing for synthesizing the received signal 7. Therefore, the processing performed by the receiving device 305 can be simplified. Also, the receiving device 30
The configuration of 5 can be simplified.

[Third Embodiment] Next, the third embodiment of the present invention will be described.
A communication system and a communication method according to the embodiment will be described. The communication system according to the third embodiment includes a receiving device 505 shown in FIG. 18 as a receiving device.

(Receiver) As shown in FIG. 18, the receiver 505 includes a plurality of antennas 51 _{1 to} 51n, a plurality of signal processors 552 _{1 to} 552n, and a weight controller 508.
A plurality of antenna weight multiplication units 553, an antenna signal synthesis unit 554, a serial / parallel conversion unit 56, and a data demodulation unit 5
7, error correction decoding unit 58, information symbol restoration unit 59
With. Further, the signal processing units 552 _{1 to} 552n include a symbol timing synchronization unit 52a, a guard interval removal unit 52b, a time frequency conversion unit 52c, a spread code generation unit 52d, a plurality of spread code multiplication units 52e, and a plurality of spread code multiplication units 52e. A subcarrier weight multiplication unit 552f and a plurality of symbol combination units 552g are provided.

A plurality of antennas 51 _{1 to} 51 n, a serial / parallel conversion unit 56, a data demodulation unit 57, and an error correction decoding unit 5
8, an information symbol restoration unit 59, a symbol timing synchronization unit 52a, a guard interval removal unit 52b,
A time frequency conversion unit 52c, a spread code generation unit 52d,
The spreading code multiplication unit 52e is substantially the same as the reception device 5 shown in FIG. Therefore, in FIG. 18, the same reference numerals are given and the description thereof is omitted.

After the plurality of antennas 51 _{1 to} 51 n receive the transmission signal 6, the spreading code multiplication unit 52 e outputs the reception signal 7.
Until it is multiplied by the spreading code, the receiving device 5 shown in FIG.
Processing similar to is performed. The spread code multiplication unit 52e inputs the received signal 7 multiplied by the spread code to the subcarrier weight multiplication unit 552f.

Weight control section 508 includes antenna weight control section 581 and subcarrier weight control section 582.
The weight control unit 508 adjusts the antenna weight and the subcarrier weight so that the spread codes of the plurality of information channels # 1 to #n are orthogonal to each other. Weight control section 508 preferably adjusts the antenna weight and the subcarrier weight so that the spread codes of the plurality of information channels # 1 to #n are orthogonal to each other and the SNR is large. Weight control unit 50
8 adjusts the antenna weight and the subcarrier weight,
The antenna weight and the subcarrier weight are individually calculated.

The antenna weight controller 581 determines the antenna weight using the selective combining method, the equal gain combining method, the maximum ratio combining method, or the like. As the antenna weight control unit 581, the antenna weight control units 811 to 813 shown in FIG. 9 can be used. The subcarrier weight controller 582 determines whether the OR
Subcarrier weights are determined using C, MRC, EGC, MMSEC, etc. As the subcarrier weight controller 582, the subcarrier weight controllers 821 to 828 shown in FIG. 11D and FIG. 12 can be used.

[0194] sub-carrier weight multiplier unit 552f of the respective signal processing unit ₅₅₂ 1 ～552N, the signal processor ₅₅₂ 1-5
The received signal 7 for each subcarrier received by the antennas 51 _{1 to} 51n where 52n processes the signal is multiplied by the subcarrier weight. The subcarrier weight multiplication units 552f are provided for each of a plurality of subcarriers. Each subcarrier weight multiplication unit 552f multiplies the received signal 7 for each subcarrier input from each spreading code multiplication unit 52e by the subcarrier weight. Each subcarrier weight multiplication unit 552f inputs the received signal 7 for each subcarrier multiplied by the subcarrier weight to the symbol combination unit 552g.

The symbol combining section 552g of each of the signal processing sections 552 _{1 to} 552n receives the reception signal 7 for each subcarrier received by the antennas 51 _{1 to} 51n for which the signal processing sections 552 _{1 to} 552n process signals. The spread codes of the information channels # 1 to #n corresponding to the signal 7 are combined over the spread code period. The symbol synthesizing unit 552g synthesizes the received signal 7 for each subcarrier multiplied by the subcarrier weight input from the subcarrier weight multiplying unit 552f over the spreading code period. In this way, despreading is performed. The symbol combining unit 552g inputs the combined received signal 7 to the antenna weight multiplying unit 553.

Antenna weight multiplication section 553 multiplies the despread received signal 7 input from symbol combination section 552g of each signal processing section 552 _{1 to} 552n by the antenna weight. The antenna weight multiplication units 553 are provided by the number of the symbol combining units 552g of all the signal processing units 552 _{1 to} 552n. Each antenna weight multiplication unit 553 inputs the received signal 7 multiplied by the antenna weight to the antenna signal synthesis unit 554. The antenna signal combining unit 554 uses the received signal 7 input from the antenna weight multiplication unit 553 as the antenna 51.
The synthesis between _{1 ~51n.} In this way, spatial diversity combining is performed.

In the receiving device 505, the spread code multiplication unit 52
e multiplies the received signal 7 for each subcarrier by the spreading code, and the subcarrier weight multiplication unit 552f multiplies the received signal 7 for each subcarrier by the subcarrier weight. Then
The symbol synthesizing unit 552g synthesizes the received signal 7 multiplied by the subcarrier weight over the spreading code period and performs despreading. As a result of combining by the symbol combining unit 552g, the information symbol before being multiplied by the spreading code in the transmitting device 4 is restored. After that, the antenna weight multiplication unit 553
However, the antennas 51 ₁ to
The received signal 7 for each 51n is multiplied by the antenna weight. Then, the antenna signal combining unit 554 performs the despreading and then the received signal 7 multiplied by the antenna weight to the antenna 5
Spatial diversity combining for combining 1 _{1 to} 51n is performed.

The received signal 7 synthesized by the antenna signal synthesizer 554 is input to the serial / parallel converter 56.
After that, the same processing as that of the receiving device 5 shown in FIG. 7 is performed, and the information symbol is output.

As in the receiving device 305 shown in FIG. 18, the subcarrier weight multiplying unit 552f multiplies the received signal 7 for each subcarrier multiplied by the spread code by the subcarrier weight, and the symbol combining unit 552g produces the result. , The antenna weight multiplication unit 55
When the antenna 3 synthesizes the received signal 7 for each of the antennas 51 _{1 to} 51 n by the antenna weight, and the antenna signal combining unit 554 performs the space diversity combining for combining the received signals 7 between the antennas, the antenna weight control unit 581 , Based on the subcarrier weight that is multiplied by the received signal 7 first, it is determined whether to maintain the state of the received signal multiplied by the subcarrier weight or readjust the state of the received signal multiplied by the subcarrier weight. . Then, the antenna weight controller 581
It is preferable to adjust the antenna weight based on the determination result. Further, in this case, the subcarrier weight controller 58
2 determines subcarrier weights using MMSEC,
The antenna weight controller 581 preferably determines the antenna weight using the equal gain combining method.

Weight control section 508 acquires antenna weight information and subcarrier weight information from received signal 7 when the selective combining method, maximum ratio combining method, ORC, MRC, MMSEC, etc. are used. As shown in FIG. 18, the antenna weight control unit 581 includes a reception signal 7 for each antenna that is combined by the symbol combining unit 552g over the spreading code period.
From the antenna weight information. Then, the antenna weight control unit 581 determines the antenna weight based on the reception signal 7 for each antenna that is combined by the symbol combining unit 552g over the spreading code period. According to this, the antenna weight control unit 581 actually determines the antenna weight in consideration of the influence of the interference between the information channels in the received signal 7 which is actually multiplied by the subcarrier weight and combined over the spreading code period. it can. Therefore, the influence of interference between the information channels of the information symbol can be reduced more appropriately, and the signal transmission characteristic can be further improved.

Further, the antenna weight controller 581 obtains antenna weight information from the received signal 7 after being multiplied by the subcarrier weight by the subcarrier weight multiplier 552f and before being combined by the symbol combiner 552g. You may. According to this, it is possible to determine the antenna weight based on the antenna weight information after the influence of the spreading code multiplication in the transmission apparatus is removed and the subcarrier weight is multiplied. Therefore, the antenna weight control unit 582 can determine the antenna weight in consideration of the influence of the reception signal 7 being multiplied by the subcarrier weight, and the reception signal from which the influence of the spreading code is removed is removed. Since 7 is used, a more appropriate antenna weight can be obtained.

Further, the antenna weight controller 581 receives the received signal 7 after being multiplied by the spreading code by the spreading code multiplier 52e and before being multiplied by the subcarrier weight by the subcarrier weight multiplier 552f, The received signal 7 after the guard interval is removed by the guard interval removal unit 52b and before the time-frequency conversion processing is performed by the time-frequency conversion unit 52c, and the reception signal 7 for each subcarrier by the time-frequency conversion unit 52c.
The antenna weight information may be acquired from the received signal 7 that has been separated into the above-described one and has not been multiplied by the spread code by the spread code multiplication unit 52e.

On the other hand, the subcarrier weight controller 582
As shown in FIG. 18, the subcarrier information is acquired from the received signal 7 after being multiplied by the spreading code by the spreading code multiplication unit 52e and before being multiplied by the subcarrier weight by the subcarrier weight multiplication unit 552f. . According to this, the subcarrier weight control unit 582 can determine a more appropriate antenna weight based on the subcarrier weight information acquired from the received signal 7 from which the influence of the spread code multiplication in the transmission device 4 has been removed. . Further, the subcarrier weight control unit 582 may acquire the subcarrier weight information from between the time frequency conversion unit 52c and the spread code multiplication unit 52e.

As the sub-carrier weight controller 582, the sub-carrier weight controllers 824, 825, 827 shown in FIGS. 11 (d), 12 (d), (f) and (g) are used.
When 828 is used, subcarrier weight information is acquired from the received signal 7 that has been despread by the symbol combining unit 552g. According to this, the subcarrier weight control unit 582 can use the acquired subcarrier weight information as it is, and thus the processing can be simplified.

As the subcarrier weight controller 582, the subcarrier weight controller 82 shown in FIG.
When 6 is used, it is preferable to acquire the subcarrier weight information from the received signal 7 that is separated for each subcarrier. Then, the subcarrier weight controller 582
It is preferable to determine the subcarrier weight based on the received signal 7 for each subcarrier. According to this, the channel estimation unit 826a, the noise power estimation unit 826b, and the code multiplexing number estimation unit 826c respectively estimate the channel estimation value, the noise power estimation value, and the code multiplexing number estimation value for each subcarrier. You can

(Communication Method) Next, the case of receiving a received signal using the receiving apparatus 505 shown in FIG. 18 will be described. As shown in FIG. 19, the receiving device 505 performs steps (S401) to (S405). Steps (S401) to (S405) are substantially the same as steps (S201) to (S205) shown in FIG.

Next, receiving apparatus 505 determines subcarrier weights, and determines the determined subcarrier weights to antenna 5
The reception signal 7 for each subcarrier received by _{11 to} 51n is multiplied (S406). Then, the receiving device 505 synthesizes the received signal 7 over the spread code period (S40).
7). In this way, despreading is performed. As a result, the information symbol before being multiplied by the spreading code in the transmitting device is restored. Next, the receiving apparatus 505 determines the antenna weight, and uses the determined antenna weight as the antenna 5
The received signal 7 for each of 1 _{1 to} 51n is multiplied (S408).
Then, the receiving apparatus 505 combines the reception signals 7 among the antennas ₅₁ 1 _~51n. In this way, space diversity combining is performed (S409).

Next, as shown in FIG.
5 performs step (S410) -step (S413). Step (S410) to Step (S413)
Indicates steps (S210) to (S21) shown in FIG.
Substantially the same as 3).

(Effect) According to the communication system, the receiving device 505, and the communication method as described above, substantially the same effects as those of the communication system 1, the receiving device 5, and the communication method shown in FIGS. 1, 7, and 14 are obtained. be able to. Further, in the antenna weight multiplication unit 553, the spread code multiplication unit 52e multiplies the received signal 7 by the spread code of the information channels # 1 to #n corresponding to the received signal 7, and the subcarrier weight multiplication unit 552f generates the sub signal. The antennas 51 _{1 to} 51 n are arranged after the received signal 7 for each carrier is multiplied by the subcarrier weight, and the symbol combining unit 552 g performs despreading to combine the received signal 7 multiplied by the subcarrier weight over the spreading code period. Each received signal 7 is multiplied by the antenna weight. Then, the antenna signal combining unit 554 performs space diversity combining in which the received signal 7 multiplied by the antenna weight is combined between the antennas after the despreading is performed.

Therefore, the antenna weight controller 581 is
The received signal 7 after being multiplied by the spreading code, multiplied by the subcarrier weight, and combined over the spreading code period, that is,
The antenna weight can be determined in consideration of the influence of interference between the information channels in the received signal 7 after despreading. Then, the antenna weight multiplication unit 553 multiplies the antenna weight. Finally, the antenna signal combining unit 554 combines the reception signal 7 multiplied by the antenna weight obtained in consideration of the influence of interference between the information channels # 1 to #n, between the antennas. Therefore, the receiving device 505
Can more appropriately reduce the influence of interference between information channels of information symbols, and can further improve signal transmission characteristics.

[Fourth Embodiment] Next, a fourth embodiment of the present invention will be described.
A communication system and a communication method according to the embodiment will be described. The communication system according to the fourth embodiment includes a receiving device 605 shown in FIG. 20 as a receiving device.

(Receiver) As shown in FIG. 20, the receiver 605 includes a plurality of antennas 51 _{1 to} 51n, a plurality of signal processors 651 _{1 to} 652n, and a weight controller 608.
, Antenna signal synthesis unit 653, and time frequency conversion unit 6
54, a spread code generation unit 655, a plurality of spread code multiplication units 656, a plurality of subcarrier weight multiplication units 657,
A plurality of symbol composition units 658, a serial / parallel conversion unit 56,
The data demodulation unit 57, the error correction decoding unit 58, and the information symbol restoration unit 59 are provided. Also, the signal processing units 652 _1-
652n is a symbol timing synchronization unit 52a, a guard interval removal unit 52b, an antenna weight multiplication unit 6
52c.

[0213] a plurality of antennas ₅₁ 1 _~51n, a serial-to-parallel conversion unit 56, a data demodulation unit 57, error correction decoder 5
8, the information symbol restoration unit 59, the symbol timing synchronization unit 52a, and the guard interval removal unit 52b,
It is substantially the same as the receiving device 5 shown in FIG. Therefore, in FIG. 20, the same reference numerals are given and the description thereof is omitted.
From a plurality of antennas 51 ₁ ~51n receives a transmission signal 6, the guard interval removing unit 52b is received signal 7 to remove the guard interval, the same processing as the receiving apparatus 5 shown in FIG. 7 is performed ..

Weight control section 608 includes antenna weight control section 681 and subcarrier weight control section 682.
The weight control unit 608 adjusts the antenna weight and the subcarrier weight so that the spread codes of the plurality of information channels # 1 to #n are orthogonal to each other. Weight control section 608 preferably adjusts the antenna weight and the subcarrier weight so that the spread codes of a plurality of information channels # 1 to #n are orthogonal to each other and the SNR is large. Weight control unit 60
8 adjusts the antenna weight and the subcarrier weight,
The antenna weight and the subcarrier weight are individually calculated.

The antenna weight controller 681 determines the antenna weight using the selective combining method, the equal gain combining method, the maximum ratio combining method, or the like. As the antenna weight controller 681, the antenna weight controllers 811 to 813 shown in FIG. 9 can be used. The subcarrier weight control unit 682 uses the OR
Subcarrier weights are determined using C, MRC, EGC, MMSEC, etc. As the subcarrier weight controller 682, the subcarrier weight controllers 821 to 828 shown in FIG. 11D and FIG. 12 can be used. The antenna weight control unit 681 uses the signal processing units 652 _{1 to} 652n.
The antenna weight is input to the antenna weight multiplying unit 652c. The subcarrier weight control unit 682 inputs the subcarrier weight to the subcarrier weight multiplication unit 657.

The antenna weight multiplication unit 652c of each of the signal processing units 652 _{1 to} 652n has the signal processing units 652 _{1 to} 652n.
The received signal 7 received by the antenna processed by n is multiplied by the antenna weight. Each antenna signal processing unit 652 ₁ ~
The antenna weight multiplication unit 652c of 652n has only to multiply one received signal 7 received by each of the antennas 51 _{1 to} 51n by the antenna weight. Therefore, each of the signal processing units 652 ₁ to 652 ₁ to
One may be provided for each 652n. Therefore, the signal processing unit 65
Configuration of 2 ₁ ~652n is simplified. Each signal processing unit 6
52 ₁ ~652n antenna weight multiplying unit 652c is the antenna signal combining unit 653 inputs the reception signals 7 multiplied by the antenna weights.

Antenna signal synthesizing unit 653 synthesizes received signal 7 input from antenna weight multiplying unit 652c of each signal processing unit 652 _{1 to} 652n, between antennas 51 _{1 to} 51n. In this way, spatial diversity combining is performed. The antenna signal synthesizer 653 is configured to operate the antenna 51.
_The reception signal 7 synthesized between _{1 to} 51n is input to the time frequency conversion unit 654. The time frequency conversion unit 654 receives the signals from the antennas 51 ₁ to 5 ₁ inputted from the antenna signal synthesis unit 653.
The reception signal 7 after being combined between 51n is subjected to time-frequency conversion and separated into reception signals 7 for each subcarrier. The time frequency conversion unit 654 inputs the reception signal 7 separated for each subcarrier to the spreading code multiplication unit 656.

Spreading code generating section 655 generates a spreading code similar to the spreading code by which received signal 7 is multiplied. The spread code generation unit 655 inputs the generated spread code to the spread code multiplication unit 656. The spreading code multiplication unit 656 is provided in the antenna 51 separated by the time frequency conversion unit 654.
Information channels # 1 to # 1 that have transmitted the received signal 7 to the received signal 7 for each subcarrier after being combined between _{1 to} 51n
The spreading code of #n is multiplied in the frequency axis direction. By being multiplied by the spreading code in this way, the reception signal 7 is removed from the influence of the spreading code being multiplied by the transmitting device. The spreading code multiplication units 656 are provided by the number of a plurality of subcarriers. Each spread code multiplication unit 656 multiplies the received signal 7 for each subcarrier after being combined between the antennas 51 _{1 to} 51 n by the spread code. The spread code multiplication unit 656 inputs the received signal 7 multiplied by the spread code to the subcarrier weight multiplication unit 657.

The subcarrier weight multiplication unit 657 multiplies the received signal 7 for each subcarrier input from each spreading code multiplication unit 52e by the subcarrier weight. The number of subcarrier weight multiplication units 657 is equal to the number of subcarriers. Each subcarrier weight multiplication unit 657 inputs the received signal 7 for each subcarrier multiplied by the subcarrier weight to the symbol combination unit 658. Symbol synthesis unit 658
Is the received signal 7 input from the subcarrier weight multiplication unit 657 for each subcarrier after being combined between the antennas.
To the information channels # 1 to #n corresponding to the received signal 7.
The spread code is combined over the spread code period. In this way, despreading is performed.

In the receiver 605, each signal processing unit 652
The antenna weight multiplication unit 652c of _{1 to} 652n multiplies the received signal 7 by the antenna weight, and the antenna signal synthesis unit 65
3 synthesizes between the antennas 51 _{1 to} 51 n. Next, the time-frequency conversion unit 654 separates the reception signal 7 after being combined between the antennas into reception signals for each subcarrier.
Then, the spreading code multiplication unit 656 causes the antennas 51 _{1 to} 5 ₁
The received signal 7 for each subcarrier after being combined for 1n is multiplied by the spread code. Finally, the subcarrier weight multiplication unit 657 multiplies the reception signal 7 for each subcarrier after combining between the antennas 51 _{1 to} 51n by the subcarrier weight, and the symbol combining unit 658 combines the spread code periods. To do. As a result, despreading is performed. As a result of combining by the symbol combining unit 658, the information symbol before being multiplied by the spreading code in the transmitting device is restored.

The received signal 7 synthesized by the symbol synthesizing unit 658 is input to the serial / parallel converting unit 56. After that, the same process as the receiving device 5 shown in FIG. 7 is performed,
Information symbols are output.

As in the receiving apparatus 605 shown in FIG. 20, the antenna weight multiplication unit 652c has the antennas 51 _{1 to} 5 _1.
The subcarrier weight multiplication unit 657 multiplies the reception signal 7 for each 1n by the antenna weight, and the antenna signal combination unit 653 performs space diversity combination for combining the reception signal 7 multiplied by the antenna weight between the antennas. , The despreading that multiplies the received signal 7 for each subcarrier multiplied by the spreading code by the subcarrier weight, and the symbol synthesis unit 658 synthesizes the received signal 7 multiplied by the subcarrier weight over the spreading code period. When performing, the subcarrier weight control unit 682 maintains the state of the reception state 7 in which the antenna weight is multiplied based on the antenna weight which is previously multiplied by the reception signal 7, or the reception signal in which the antenna weight is multiplied. It is judged whether the state of 7 is to be readjusted. Then, subcarrier weight control section 682 preferably adjusts the subcarrier weight based on the determination result. Further, in this case, the antenna weight control unit 681 determines the antenna weight using the equal gain combining method, and the subcarrier weight control unit 682
It is preferred to use either MMSEC or EGC to determine subcarrier weights.

Weight control section 608 acquires antenna weight information and subcarrier weight information from received signal 7 when the selective combining method, maximum ratio combining method, ORC, MRC, MMSEC, etc. are used. As shown in FIG. 20, the antenna weight controller 681 detects the antenna from the received signal 7 after the guard interval is removed by the guard interval remover 52b and before the antenna weight multiplier 652c multiplies the antenna weight. Get information.

The subcarrier weight controller 682 causes the antenna signal combiner 653 to transmit the received signal 7 to the antenna 5
1 _{1 to} 51n are combined, and the time-frequency conversion unit 654 separates the received signal for each subcarrier, and the spread code multiplication unit 656 multiplies the spread code by the subcarrier weight multiplication unit 657. The subcarrier weight information is obtained from the received signal 7 before being multiplied by the subcarrier weight. According to this, the subcarrier weight controller 682 can obtain the subcarrier weight in consideration of the influence of the reception signal 7 being multiplied by the antenna weight and being combined between the antennas 51 _{1 to} 51 n.

Further, subcarrier weight control section 682 can use the subcarrier weight information acquired from received signal 7 from which the effect of multiplication of the spreading code in the transmission apparatus has been removed. Therefore, a more appropriate subcarrier weight can be obtained. Also, the subcarrier weight controller 6
Reference numeral 82 denotes subcarrier weight information obtained from the reception signal 7 after being separated by the time-frequency conversion unit 654 into the reception signals 7 for each subcarrier and before being multiplied by the spreading code by the spreading code multiplication unit 656. You may.

As the sub-carrier weight controller 682, the sub-carrier weight controllers 824, 825, 827 shown in FIGS. 11 (d), 12 (d), (f) and (g) are used.
When 828 is used, subcarrier weight information is acquired from the received signal 7 that has been despread by the symbol combining unit 658. According to this, the subcarrier weight control unit 682 can use the acquired subcarrier weight information as it is, and thus the processing can be simplified.

As the subcarrier weight controller 682, the subcarrier weight controller 82 shown in FIG.
When 6 is used, it is preferable to acquire the subcarrier weight information from the received signal 7 that is separated for each subcarrier. Then, the subcarrier weight controller 682
It is preferable to determine the subcarrier weight based on the received signal 7 for each subcarrier. According to this, the channel estimation unit 826a, the noise power estimation unit 826b, and the code multiplexing number estimation unit 826c respectively estimate the channel estimation value, the noise power estimation value, and the code multiplexing number estimation value for each subcarrier. You can

In the receiving device 605, the time frequency
The conversion unit 654 is replaced by each signal processing unit 652. ₁~ 652n smell
And is provided next to the antenna weight multiplication unit 652c.
May be. In this case, each signal processing unit 652₁~ 652n
The time-frequency converter of the
The signal 7 is input to the antenna signal synthesis unit 653. This
Even with such a configuration, the antenna weight multiplication unit 652c is
Its antenna 51₁One received signal received by ~ 51n
7 may be multiplied by the antenna weight, and each signal processing unit 65
Two₁It is only necessary to provide one for each of ~ 652n. Yo
The signal processing unit 652₁~ 652n configuration is simplified
It

(Communication Method) Next, the case of receiving a received signal using the receiving apparatus 605 shown in FIG. 20 will be described. As shown in FIG. 21, the receiving device 605 performs steps (S501) to step (S503). Steps (S501) to (S503) are substantially the same as steps (S201) to (S203) shown in FIG.

[0230] Next, the receiving apparatus 605 determines the antenna weight, the determined antenna weights, the antenna ₅₁ 1-5
The received signal 7 for every 1n is multiplied (S504). And
Receiving apparatus 605 combines the reception signals 7 among the antennas ₅₁ 1 _~51n (S505). In this way, spatial diversity combining is performed. Next, the receiving device 605
The received signal 7 is time-frequency converted, and the received signal 7 spread over a plurality of subcarriers having different frequencies is separated into the received signal 7 for each subcarrier (S506). Receiver 60
5 generates a spreading code similar to the spreading code multiplied by the received signal 7. Then, the receiving apparatus 605, the reception signal 7 received by the plurality of antennas ₅₁ 1 _~51n
Is multiplied by the spread code of the information channel corresponding to the received signal 7 (S507).

Next, receiving apparatus 605 determines a subcarrier weight, and the received signal for each subcarrier is multiplied by the determined subcarrier weight (S50).
8). Then, the receiving device 605 synthesizes the received signal 7 over the spread code period (S509). In this way, despreading is performed. As a result, the information symbol before being multiplied by the spreading code in the transmitting device is restored.
Next, as illustrated in FIG. 20, the receiving device 605 performs steps (S510) to step (S513). Steps (S510) to (S513) are substantially the same as steps (S210) to (S213) shown in FIG.

(Effect) According to the communication system, the receiving device 605, and the communication method as described above, substantially the same effects as those of the communication system 1, the receiving device 5, and the communication method shown in FIGS. 1, 7, and 14 are obtained. be able to. Further, the time frequency conversion unit 6
Before 54 separates the received signal 7 into the received signal 7 for each subcarrier, the antenna weight multiplication unit 652c causes the antenna 5
The received signal 7 for each of 1 _{1 to} 51n is multiplied by the antenna weight,
The antenna signal combining unit 653 uses the antennas 51 _{1 to} 51n.
The received signal 7 is synthesized between them. After that, the time-frequency conversion unit 654 separates the received signal for each subcarrier. Then, subcarrier weight multiplication section 657 multiplies received signal 7 for each subcarrier by the subcarrier weight. Finally,
The symbol combining unit 658 combines the received signal 7 multiplied by the subcarrier weight over the spreading code period.

Therefore, the time-frequency conversion unit 654, the subcarrier weight multiplication unit 657 and the symbol synthesis unit 658.
Is a process of separating the received signal 7 into the received signals 7 of the subcarriers, a process of multiplying the subcarrier weights, and a received signal 7 individually for each of the received signals of the plurality of antennas 51 _{1 to} 51n.
It is not necessary to perform the processing of synthesizing over the spread code period. That is, the time-frequency conversion unit 654, the subcarrier weight multiplication unit 657, and the symbol combination unit 658 collectively receive the received signal 7 for each subcarrier with respect to the received signal 7 combined between the plurality of antennas 51 _{1 to} 51 n. Received signal 7
, A process of multiplying the subcarrier weights, and a process of synthesizing the received signal 7 over the spread code period.

[Fifth Embodiment] Next, the fifth embodiment of the present invention will be described.
A communication system according to the embodiment will be described. The communication system according to the fifth embodiment includes a transmitter 404 shown in FIG. 22 or a transmitter 504 shown in FIG. 24 as a transmitter.

(Transmission Device) As shown in FIG. 22, the transmission device 404 includes a plurality of signal processing units 441 _{1 to} 441 n.
The signal combining unit 442, the frequency / time converting unit 43, the guard interval inserting unit 44, and the antenna 45 are provided.
The signal processing units 441 _{1 to} 441 n include the information symbol generation unit 41 a, the error correction coding unit 41 b, and the data modulation unit 4.
1c, a serial-parallel converter 241d, and a spread code generator 41
e, a plurality of symbol duplicating units 241f, a plurality of spreading code multiplying units 241g, a propagation path fluctuation amount estimating pilot symbol inserting unit 441h, a weight updating pilot signal inserting unit 441i, and an in-information-channel signal combining unit 441j. With.

The information symbol generator 41a, the error correction encoder 41b, the data modulator 41c, the spread code generator 41e, the frequency time converter 43, and the guard interval inserter 44 are shown in FIG. It is substantially the same as the transmitter 4. Further, the serial / parallel conversion unit 241d, the plurality of symbol duplication units 241f, and the plurality of spreading code multiplication units 241g.
Is substantially the same as the transmission device 204 shown in FIG. Therefore, the description is omitted in FIG.

The propagation path fluctuation amount estimation pilot symbol inserting section 441h inserts the propagation path fluctuation amount estimation pilot symbol into the information symbol. As a result, the transmission signal 6 in which the information signal and the propagation path variation amount estimation pilot signal are multiplexed is generated. As the propagation path variation estimation pilot symbol, a symbol whose amplitude and phase are known in the receiving apparatus 5 is used. The channel-variation-amount estimation pilot symbol is used in the receiver to estimate the channel-variation amount of the received signal.

Weight updating pilot signal inserting section 441i
Inserts the weight update pilot signal into the information signal.
As a result, the transmission signal 6 in which the information signal and the weight update pilot signal are multiplexed is generated. The weight update pilot signal is obtained by multiplying the weight update pilot symbol by a spreading code. The weight update pilot symbol is
In the receiver 5, symbols whose amplitude and phase are known are used. The weight update pilot symbol is used in the receiver for estimating an error between the information signal received by the receiver after despreading and the information signal transmitted by the transmitter.
The weight update pilot symbol is used when estimating an error between the despread reception signal and the transmission signal in order to update the subcarrier weight. Thus, inserting the weight update pilot symbol means not only inserting the weight update pilot symbol itself into the information symbol, but also the weight update pilot signal obtained by multiplying the weight update pilot symbol by the spread code as the information signal. Also included when inserting into. Therefore, the weight updating pilot signal inserting section 441i functions as a weight updating pilot symbol inserting section that inserts the weight updating pilot symbol into the information symbol. It should be noted that a common pilot symbol may be used for a plurality of information channels # 1 to #n as the propagation path variation estimation pilot symbol and the weight update pilot symbol, and each information channel # 1 to #n may be used.
, Different pilot symbols may be used.

The in-information-channel signal combiner 441j combines the information signal, the propagation path fluctuation amount estimation pilot signal, and the weight update pilot signal for each of the information channels # 1 to #n. The transmitter 404 multiplexes the weight update pilot signal and the information signal by code multiplexing in the spreading code axis direction. Then, in the transmitter 404, the code-multiplexed weight update pilot signal and information signal,
The propagation path variation estimation pilot signal is multiplexed by time multiplexing in the time axis direction.

[0240] From information symbol generating section 41a to data modulating section 41c, the same processing as in transmitting apparatus 4 shown in Fig. 2 is performed. The data modulation unit 41c and the propagation path fluctuation amount estimation pilot symbol insertion unit 441h input the information symbol and the propagation path fluctuation amount estimation pilot symbol to the serial-parallel conversion unit 241d at mutually different times. As a result, the information symbol and the propagation path fluctuation amount estimation pilot symbol are time-multiplexed. Specifically, the information symbol input to the serial / parallel conversion unit 241d by the data modulation unit 41c and the pilot symbol insertion unit 44 for estimating the channel fluctuation amount.
1h is switched to the pilot symbol for estimating the channel fluctuation amount which is input to the serial-parallel converter 241d to switch the serial-parallel converter 2
By the switching unit inputting into 41d, the information symbol,
The propagation path variation estimation pilot symbols are input to the serial-parallel conversion unit 241d at different times.

From the serial / parallel conversion unit 241d to the spread code multiplication unit 241g, the same processing as that of the transmission device 204 shown in FIG. 4 is performed. However, the spreading code multiplying unit 241g multiplies the propagation path variation estimation pilot symbol and the information symbol by different spreading codes. Spread code multiplication unit 241g
Inputs the time-multiplexed information signal multiplied by the spread code and the propagation path fluctuation amount estimation pilot signal to the in-information-channel signal combining section 441j.

The in-information-channel signal combiner 441j combines the information signal transmitted on the information channels # 1 to #n and the propagation path fluctuation amount estimation pilot signal. The in-information-channel signal combiner 441 j inputs the combined information signal and the propagation path variation estimation pilot signal to the signal combiner 442. Weight update pilot signal insertion unit 441i
Is a weight update pilot signal obtained by multiplying the weight update pilot symbol by the same spread code as the spread code multiplied by the propagation path variation estimation pilot symbol in the signal processing units 441 _{1 to} 441 n. Synthesizer 44
Enter 2.

The signal synthesizing unit 442 determines each information channel # 1.
To #n signal processing units 441 _{1 to} 441 n, the time-multiplexed information signals and pilot signals for estimating the channel fluctuation amount, which are input from the in-information-channel signal combining units 441 j, and the pilot signal insertion unit 441 i are input. Code multiplexing is performed with the weight update pilot signal. After that, the same processing as that of the transmission device 4 shown in FIG. 2 is performed from the frequency-time conversion unit 43 to the antenna 45.

As a result, the transmission signal 6d shown in FIG. 23 is obtained. The transmission signal 6d is the weight update pilot signal 6
3d and the information signal 61d are code-multiplexed in the spreading code axis direction, and the weight update pilot signal 63d and the information signal 61 are added.
d and the propagation path variation estimation pilot signal 62d are time-multiplexed in the time axis direction. The propagation path fluctuation amount estimation pilot signal 62d and the weight update pilot signal 63d are time-multiplexed with the same spreading code. Then, the transmission signal 6d is spread in the frequency axis direction and becomes a multi-carrier CDMA signal.

In this way, transmitting apparatus 404 is provided with channel variation estimation pilot symbol inserting section 441h and weight updating pilot signal inserting section 441i individually. Therefore, the transmitting apparatus 404 updates the optimum channel fluctuation amount estimation pilot symbol for estimating the channel fluctuation amount and the optimum weight update for estimating the error between the despread reception signal and the transmission signal. The pilot symbols for use can be transmitted separately. Furthermore, the transmitting device 404
Can generate the transmission signal 6d by a multiplexing method suitable for each pilot symbol. For example,
As shown in FIG. 23, the weight update pilot signal 63d
Requires a long time, and if time-multiplexed with the information signal 61d, the frame efficiency becomes poor. Therefore, for the weight update pilot signal 63d, frame efficiency can be improved by adopting code multiplexing. The propagation path fluctuation estimation pilot signal 62d is used only for a short time. Therefore, for the propagation path fluctuation amount estimation pilot signal 62d, time-multiplexing is adopted so that intersymbol interference in the portion of the propagation path fluctuation amount estimation pilot signal 62d can be prevented. As a result, it is possible to improve the accuracy of estimation of the propagation path fluctuation amount performed by the receiving device.

Note that, as in the transmitting device 504 shown in FIG. 24, the signal processing sections 541 ₁ to 541 ₁ to 541 of the respective information channels # 1 to #n.
A channel fluctuation amount for inserting the channel fluctuation amount estimation pilot symbol into the serial / parallel conversion unit 241d in order to time-multiplex the information signal and the channel fluctuation amount estimation pilot signal or the weight update pilot signal into the 541n. Estimation pilot symbol insertion unit 441h and serial-parallel conversion unit 241d
A weight update pilot symbol inserting section 541i for inserting the weight update pilot symbol may be provided in the. Further, in order to code-multiplex the information signal and the pilot signal for estimating the fluctuation amount of the propagation path and the pilot signal for updating the weight, the pilot signal for estimating the fluctuation amount of the propagation path is inserted in the signal combining unit 442. A weight updating pilot signal inserting unit 441i for inserting the weight updating pilot signal may be provided in the signal inserting unit 541h and the signal combining unit 442.

According to transmitting apparatus 504 as described above, a suitable multiplexing method can be appropriately selected and combined when the information signal, the weight updating pilot signal, and the propagation path fluctuation amount estimating pilot signal are multiplexed. Therefore, the transmission device 504 can generate an optimum transmission signal.

(Receiver) When the received signal 7 including the propagation path variation estimation pilot symbol and the weight update pilot symbol is received from the transmitters 404 and 504, FIG. 7, FIG. 10, FIG. 18, and FIG. The receiving devices 5, 205, 505, and 605 shown in FIG.
It is possible to use a subcarrier weight controller 829 as shown in FIG. Also, the weight control unit 308 shown in FIG.
Can have the configuration of the subcarrier weight controller 829.

As shown in FIG. 25, subcarrier weight control section 829 includes channel estimation section 829a, noise power estimation section 829b, code multiplexing number estimation section 829c, weight calculation section 829d, and error estimation section 829e. A reference symbol holding unit 829f, a weight updating unit 829g, and a switching unit 829h are provided.

The channel estimation unit 829a, the noise power estimation unit 829b, and the code multiplex number estimation unit 829c use the propagation path variation amount estimation pilot symbol 72a for estimating each value, except for FIG. 12 (e). Channel estimation section 826a, noise power estimation section 826b, and code multiplexing number estimation section 826c of subcarrier weight control section 826 shown in FIG.
And is substantially the same. In addition, the weight calculation unit 829d
The weight calculation unit 826 illustrated in FIG. 12E is used except that the determined subcarrier weight is input to the switching unit 829h.
Substantially the same as d.

Error estimation section 829e uses subcarrier weight control section 82 shown in FIG. 12 (f) except that weight update pilot symbol 72b is used to estimate the error.
7 is substantially the same as the error estimation unit 827a. Also, the reference symbol holding unit 829f is configured to transmit the transmitting devices 404 and 504.
Holds the weight update pilot symbol to be transmitted as a reference symbol. Weight update unit 82
9g is a switching unit 829 for the determined subcarrier weight.
Enter in h. Further, when the received signal 7 is first received, the weight update unit 829g does not find the subcarrier weight because there is no despread pilot symbol for estimating the error. The weight update unit 829g is the same as in FIG.
This is substantially the same as the weight updating unit 827c of the subcarrier weight control unit 827 shown in 2 (f).

The switching unit 829h includes a weight calculation unit 829.
The subcarrier weight input from d and the weight update unit 82
Subcarrier weights input from 9g are shown in FIG. 7 and FIG.
0, the receiving devices 5, 205 and 50 shown in FIGS.
5,605 subcarrier weight multiplication units 54,552f,
657 and the input to the collective weight multiplication unit 352f of the receiving device 305 illustrated in FIG.

The switching unit 829h first receives the received signal 7
When there is no pilot symbol after despreading for estimating the error, the subcarrier weight calculated by the weight calculation section 829d is used as an initial value for the subcarrier weight multiplication sections 54, 552f, 657 and the batch. Weight multiplication unit 35
Input to 2f. After that, the subcarrier weight determined by the weight update unit 829g is set to the subcarrier weight multiplication unit 5
4, 552f, 657 and the collective weight multiplication unit 352f. According to this, the received signal 7 can be multiplied by using a more appropriate initial value as the subcarrier weight. still,
The switching unit 829h includes a subcarrier weight multiplication unit 54,
Which of the weight calculation section 829d and the weight update section 829g inputs the subcarrier weight to the 552f, 657 and the collective weight multiplication section 352f can be set appropriately. Therefore, the switching method is not limited to the above.

[0254] Such a subcarrier weight controller 829
According to the above, the subcarrier weight control unit 829 uses the optimal channel fluctuation amount estimation pilot symbols for estimating the channel fluctuation amount and the like to more appropriately perform channel estimation, noise power estimation, and code multiplexing number. Can be estimated. Further, subcarrier weight control section 829 can more appropriately estimate the error by using the optimum weight update pilot symbol for estimating the error between the despread reception signal and the transmission signal. Further, the subcarrier weight controller 829
The subcarrier weights determined by the subcarrier weight calculation unit 829d and the weight update unit 829g can be selectively used according to the situation.

Note that the subcarrier weight control units 82, 282, 482, 582, 682 of the receiving devices 5, 205, 505, 605 shown in FIGS. 7, 10, 18, and 20 are shown in FIG. 11 (d). , When the subcarrier weight control units 824 to 828 shown in FIGS. 13D to 13G are used, or when the weight control unit 382 of the receiving apparatus 305 shown in FIG. 15 is used. Also in the case of having the above configuration, the subcarrier weight control units 824, 825, 82
7, 828 can use the weight update pilot symbol 72b, and the subcarrier weight controller 826
The propagation path fluctuation amount estimation pilot symbol 72a can be used.

[0256] Such a communication system and transmitting device 40
4,504, it is possible to obtain substantially the same effects as those of the communication system 1 and the transmitters 4,204,304 shown in FIGS. 1, 2, 4, and 6. Further, the pilot symbol insertion units 441h and 541h for estimating the channel fluctuation amount,
Weight update pilot symbol insertion unit 441i, 541
Since i is individually provided, the transmission devices 404 and 504 can separately transmit the propagation path fluctuation amount estimation pilot symbol and the weight update pilot symbol. Furthermore, the transmission devices 404 and 504 can generate the transmission signal 6d by using a multiplexing method suitable for each pilot symbol. Also, the receiving apparatus can more appropriately perform channel estimation, noise power estimation, and code multiplexing number estimation by using the propagation path fluctuation amount estimation pilot symbol, and by using the weight update pilot symbol, The error can be estimated appropriately.

[Sixth Embodiment] Next, the sixth embodiment of the present invention will be described.
A communication system according to the embodiment will be described. The communication system according to the sixth embodiment includes a receiving device 705 shown in FIG. 26 as a receiving device.

(Receiving Device) The receiving device 705 has a plurality of antennas 51 _{1 to} 51n and a plurality of signal processing units 752 ₁ to 752 ₁ .
752n, determination unit 752, configuration switching unit 753
And a post-diversity combination despreading unit 754, a post-despreading diversity combination unit 755, a serial-parallel conversion unit 56, a data demodulation unit 57, an error correction decoding unit 58, and an information symbol restoration unit 59. Further, the signal processing units 752 ₁ to 75
2n includes a symbol timing synchronization unit 52a, a guard interval removal unit 52b, and a received signal state measurement unit 751.
With. A plurality of antennas ₅₁ 1 _~51n, a serial-to-parallel conversion unit 56, a data demodulation unit 57, error correction decoder 5
8, the information symbol restoration unit 59, the symbol timing synchronization unit 52a, and the guard interval removal unit 52b are substantially the same as the reception device 5 shown in FIG. Therefore, in FIG. 26, the same reference numerals are given and description thereof is omitted.

The received signal status measuring section 751 is
Is a measuring unit for measuring the state of. Received signal condition measuring unit 7
The number of the antennas 51 is the same as the number of the plurality of antennas 51 _{1 to} 51 n. In the receiving device 705, the signal processing units 752 _{1 to} 752 n corresponding to the antennas 51 ₁ to 51 n include a received signal state measuring unit 751 that measures the state of the received signal 7 received by each of the antennas 51 _{1 to} 51 n. The reception signal state measuring unit 751 measures the power and fading correlation of the reception signal 7 as the state of the reception signal 7. The received signal state measuring unit 751 may measure either the power of the received signal 7 or the fading correlation, or may measure other parameters indicating the state of the received signal 7.

Specifically, each of the signal processing units 752 ₁ to 75 2
The reception signal state measuring unit 751 of 2n is connected to each antenna 51 ₁
Measure the power and fading correlation coefficient of the received signal 7 received by ~ 51n. Received signal state measuring unit 75
1 inputs the measured power value of the received signal 7 and the measured fading correlation coefficient value to the determination unit 752.
Further, the reception signal state measuring unit 751 of each of the signal processing units 752 _{1 to} 752n inputs the reception signal 7 received by each of the antennas 51 _{1 to} 51n to the configuration switching unit 753.

Judging section 752 multiplies the received signal for each subcarrier multiplied by the spreading code by the subcarrier weight,
The order of combining is controlled by multiplying the received signal for each antenna by the antenna weight and combining the signals over the spread code period. Here, the determination unit 752 controls the order of despreading and space diversity combining. Specifically, the determination unit 7
In 52, the subcarrier weight multiplication unit multiplies the reception signal for each subcarrier multiplied by the spreading code by the subcarrier weight, and the symbol combining unit spreads the reception signal multiplied by the subcarrier weight over the spreading code period. synthesizing Te processing (despreading), the antenna weight multipliers portion, the antenna ₅₁ 1-51
The reception signal 7 for each n is multiplied by the antenna weight, and the antenna signal combining unit multiplies the reception signal 7 by which the antenna weight is multiplied,
The order of performing the process of combining the antennas 51 _{1 to} 51 n (space diversity combining) is controlled.

The judging section 752 determines each of the signal processing sections 752 ₁ ...
Based on the state of the reception signals 7 each antenna 51 ₁ ~51n receives input from the reception signal condition measuring unit 751 of 752N, controls the order of the processes included in the process of despreading and space diversity combining. Here, the determination unit 752
Controls the order of despreading and spatial diversity combining based on the state of the received signal 7.

The judging section 752 determines that each of the antennas 51 _{1 to} 51
The order is controlled based on the measured value of the fading correlation coefficient of the n received signals 7. Specifically, the determination unit 752
When the fading correlation coefficient of the received signal 7 of each of the antennas 51 ₁ ~51n is high, determines to perform despreading after spatial diversity combining. On the other hand, when the fading correlation coefficient of the received signal 7 of each of the antennas 51 _{1 to} 51 n is low, the determining unit 752 determines to perform space diversity combining after despreading.

According to this, the fading correlation is high,
When the gain due to the spatial diversity combining decreases, the channel estimation accuracy can be improved by performing despreading after the spatial diversity combining. Therefore, even if the gain due to spatial diversity combining decreases,
The subcarrier weight control unit can perform channel estimation with high accuracy and can determine the optimum subcarrier weight.
Therefore, the receiving device 705 can improve the final signal transmission characteristics. On the other hand, when the fading correlation is low and the gain due to the space diversity combination is large, the antenna weight control unit performs the space diversity combination after the despreading, so that the antenna weight control unit inter-information channels in the received signal 7 after the despreading is performed. The antenna weight can be determined in consideration of the influence of the interference of, that is, the influence related to the orthogonality of the spread code. Therefore, the receiving device 705
Appropriate space diversity combining can be performed to further improve the gain and signal transmission characteristics.

Further, the judging section 752 determines that each of the antennas 51 ₁ ...
The order may be controlled based on the measured value of the power of the reception signal 7 of 51n. Specifically, determining unit 752, when the power of the received signal 7 of each of the antennas 51 ₁ ~51n is small, it is determined that despreading after spatial diversity combining. On the other hand, the determination unit 752 determines that each of the antennas 51 _{1 to} 51n.
When the power of the received signal 7 is high, it is determined that the space diversity combination is performed after despreading.

According to this, when the power of the received signal 7 is small and the channel estimation accuracy deteriorates as it is, the channel estimation accuracy can be improved by performing despreading after spatial diversity combining. Therefore, the subcarrier weight control unit can perform channel estimation with high accuracy and can determine the optimum subcarrier weight. Therefore, the receiving device 705 can improve the final signal transmission characteristics. On the other hand, when the power of the received signal 7 is high, the channel estimation accuracy is already high, and it is not necessary to further perform the processing for improving the channel estimation accuracy. Therefore, by performing space diversity combining after despreading, the antenna weight control unit allows the antenna weight controller to influence the interference between information channels in the received signal 7 after despreading,
That is, the antenna weight can be determined in consideration of the influence of the orthogonality of the spread code. Therefore, the receiving device 7
05 can improve the signal transmission characteristic. Further, the determining unit 752 controls the order of despreading and space diversity combining based on both the fading correlation coefficient of the received signal 7 and the power of the received signal 7. May be. For example, the determination unit 752 holds the threshold value of the fading correlation coefficient and the threshold value of the power, which are the determination criteria for determining the order of despreading and spatial diversity combining. First, the determining unit 752 determines that each of the antennas 51 _{1 to} 5 input from the reception signal state measuring unit 751.
The measured value of the fading correlation coefficient of the received signal 7 received by 1n is compared with the threshold value of the fading correlation coefficient. Determination unit 752, the measured values of the fading correlation factors of the reception signals 7 each antenna 51 ₁ ~51n is received when above the threshold of the fading correlation factors determines to perform the despreading after spatial diversity combining.

[0267] On the other hand, determination unit 752, the measured values of the fading correlation factors of the reception signals 7 by the antenna 51 ₁ ~51n receives input from the reception signal condition measuring unit 751, if more than the threshold of the fading correlation factors The received signal 7
It is decided to determine the order based on the electric power of. When the measured value of the fading correlation coefficient of the received signal 7 is less than or equal to the threshold value,
Determination unit 752, the reception signal 7 of all the antennas ₅₁ 1 _~51n inputted from the antenna ₅₁ 1 _~51n signal processing unit ₇₅₂ 1 ～752N reception signal condition measuring unit 751
The measured value of the power is compared with the power threshold. Determination unit 752, the measured value of the power of the received signal 7 of all the antennas 51 ₁ ~51n is, if below the threshold of power, it is determined that despreading after spatial diversity combining. On the other hand, determination unit 752, the measured value of the power of the received signal 7 of each of the antennas 51 ₁ ～51N is, when the above power threshold even one, determines to perform spatial diversity combining after despreading.

The judging section 752 inputs the order of despreading and space diversity combining thus determined to the configuration switching section 753.

The configuration switching unit 753 includes a post-diversity combining despreading unit 754 and a post-despreading diversity combining unit 75.
The input of the received signal 7 to 5 is switched. In the configuration switching unit 753, the received signal 7 received by each of the antennas 51 _{1 to} 51n is received by the signal processing unit 75 of each of the antennas 51 _{1 to} 51n.
It is input from the reception signal state measuring units 751 of 2 _{1 to} 752 n. In addition, the order of despreading and space diversity combining determined by the determination unit 752 is input to the configuration switching unit 753. Configuration switching unit 753, based on the order of despreading and space diversity combining input from the determination unit 752, a reception signal 7 of each of the antennas 51 ₁ ~51n, after diversity combining the despreading unit 754, or after despreading diversity combining Input to any of the parts 755.

When the order of performing space diversity combining after despreading is input, the configuration switching unit 753 receives each of the antennas 51 ₁ to 51 _{1 as} shown by the solid line in FIG.
The demultiplexed diversity combining unit 7 receives the received signal 7 of 51n.
Enter 55. On the other hand, the configuration switching unit 753, when the order of performing despreading after spatial diversity combining, as indicated by a dotted line in FIG. 26, the antennas 51 ₁ ~
The received signal 7 of 51n is subjected to diversity combining and then despreading section 7
54.

The post-diversity combining despreading section 754 has a structure for performing despreading after space diversity combining. The post-diversity-combining despreading unit 754 includes a time-frequency conversion unit, a spreading code generation unit, a plurality of spreading code multiplication units, a weight control unit, a plurality of antenna weight multiplication units, an antenna signal synthesis unit, and a plurality of antenna signal synthesis units. A subcarrier weight multiplication unit,
And a plurality of symbol combining units. The weight controller is
An antenna weight controller and a subcarrier weight controller are provided. The post-diversity-combining despreading unit 754 is arranged so that these components can perform despreading after performing space-diversity combining. Specifically, the receiving devices 5, 205 and 60 shown in FIGS. 7, 10 and 20.
5, the time-frequency conversion unit, the spreading code generation unit, the plurality of spreading code multiplication units, the weight control unit, the plurality of antenna weight multiplication units, the antenna signal combination unit, and the plurality of subcarrier weights. A multiplication unit and a plurality of symbol combination units can be arranged.

Then, the despreading unit 75 after diversity combining is performed.
4 is a configuration switching unit 7 based on the control of the determination unit 752.
When the reception signal 7 of each of the antennas 51 _{11 to} 51n is input from 53, the reception signal 7 is processed. Specifically, the antenna weight multiplication unit of the post-diversity combining despreading unit 754 multiplies the reception signal 7 of each of the antennas 51 _{1 to} 51n by the antenna weight, and the antenna signal combination unit multiplies the reception signal by the antenna weight. 7, antennas 51 _{1 to} 51
Spatial diversity synthesis is performed by synthesizing between n. next,
A subcarrier weight multiplication unit of the post-diversity combining despreading unit 754 multiplies the received signal 7 for each subcarrier multiplied by the spreading code by the subcarrier weight, and the symbol combining unit receives the received signal by which the subcarrier weight is multiplied. 7 is combined over the spreading code period to perform despreading. The post-diversity combining despreading unit 754 inputs the combined reception signal 7 to the serial-parallel conversion unit 56. After that, the same processing as that of the receiving device 5 shown in FIG. 7 is performed, and the information symbol is output.

Post despreading diversity combining section 755 has a configuration for performing space diversity combining after despreading. The despreading diversity combining unit 755 includes a time-frequency conversion unit, a spreading code generating unit, a plurality of spreading code multiplying units, a weight control unit, a plurality of antenna weight multiplying units, an antenna signal combining unit, and a plurality of antenna signal combining units. A subcarrier weight multiplication unit,
And a plurality of symbol combining units. The weight controller is
An antenna weight controller and a subcarrier weight controller are provided. After despreading diversity combining section 755, these components are arranged so that space diversity combining can be performed after despreading. Specifically, similar to the receiving device 505 shown in FIG. 18, a time frequency conversion unit, a spreading code generation unit, a plurality of spreading code multiplication units, a weight control unit, and a plurality of antenna weight multiplication units. , An antenna signal synthesis unit, a plurality of subcarrier weight multiplication units,
A plurality of symbol combining units can be arranged.

After despreading, the diversity combining unit 75
5 is a configuration switching unit 7 based on the control of the determination unit 752.
When the reception signal 7 of each of the antennas 51 _{1 to} 51 n is input from 53, the reception signal 7 is processed. In particular,
The subcarrier weight multiplication unit of the despread diversity combining unit 755 multiplies the reception signal 7 for each subcarrier multiplied by the spreading code by the subcarrier weight, and the symbol combining unit receives the reception signal by which the subcarrier weight is multiplied. 7 is combined over the spreading code period to perform despreading. Next, the antenna weight multiplication unit multiplies the reception signal 7 for each of the antennas 51 _{1 to} 51n by the antenna weight, and the antenna signal synthesis unit
The received signal 7 multiplied by the antenna weight is fed to the antenna 51.
_The space diversity combination is performed by combining _{1 to} 51n. The despreading diversity combining unit 755 inputs the combined reception signal 7 to the serial-parallel conversion unit 56. After that,
Processing similar to that of the receiving device 5 shown in FIG. 7 is performed, and information symbols are output.

The judging section 752 controls the order of despreading and spatial diversity combining, but is not limited to this. The judgment unit multiplies the received signal for each subcarrier multiplied by the spreading code included in the despreading process by the subcarrier weight, combines over the spreading code period (combining in despreading), and processes for spatial diversity combining. It is also possible to control the order of each processing of the multiplication of the received signal for each antenna included in the antenna weight by the antenna weight and the combining between the antennas (combining in space diversity combining).

(Communication Method) Next, the case of receiving a received signal using the receiving apparatus 705 shown in FIG. 26 will be described. As shown in FIG. 27, the receiving apparatus 705 measures the power and fading correlation factors of the reception signals 7 each antenna ₅₁ 1 _~51n received respectively (S601).
The reception device 705 compares the measured value of the fading correlation coefficient of the received signal 7 with the threshold value of the fading correlation coefficient which is a criterion for determining the order of despreading and spatial diversity combining (S602). In step (S602), receiving apparatus 705 determines to perform despreading after spatial diversity combining when the measured value of the fading correlation coefficient of received signal 7 exceeds the threshold of the fading correlation coefficient. Then, receiving apparatus 705 performs despreading after space diversity combining (S604).

On the other hand, in step (S602), if the measured value of the fading correlation coefficient of received signal 7 is less than or equal to the threshold of the fading correlation coefficient, receiving apparatus 705 receives each of antennas 51 _{1 to} 51n. The measured power value of the received signal 7 is compared with the power threshold value (S60).
3). In step (S603), the receiving device 705
Determines that despreading is to be performed after spatial diversity combining when the measured power values of the reception signals 7 of all the antennas 51 _{1 to} 51 n are below the power threshold value. Then, receiving apparatus 705 performs despreading after space diversity combining (S604). On the other hand, in step (S603),
Receiving apparatus 705, when the measured value of the power of the received signal 7 of each of the antennas 51 ₁ ～51N is more power threshold even one, determines to perform spatial diversity combining after despreading. Then, the receiving device 705 performs space diversity combining after despreading (S605).

[0278] Such a communication system and receiving device 70
5, according to the communication method, the determination unit 752, based on the state of the reception signal 7 measured by the reception signal state measurement unit 751,
Controls the order of despreading and spatial diversity combining. Then, based on the control of the determination unit 752, the configuration switching unit 7
The antennas 51 _{1 to} 51 are provided to the despreading unit 754 after diversity combining and the diversity combining unit 755 after despreading.
The n received signals 7 are input. Then, the post-diversity combining despreading unit 754 and the post-despreading diversity combining unit 755.
However, despreading and space diversity combining are performed in the order according to the control of the determination unit 752. Therefore, the receiving device 705
Despreading and space diversity combining can be performed in an appropriate order according to the state of the received signal 7 of each of the antennas 51 _{1 to} 51 n. Therefore, the receiving device 705 can further improve the signal transmission characteristics.

[Seventh Embodiment] Next, the seventh embodiment of the present invention will be described.
A communication system and a communication method according to the embodiment will be described. The communication system according to the seventh embodiment includes a receiving device 805 shown in FIG. 28 as a receiving device.

(Reception Device) As shown in FIG. 28, the reception device 805 includes a plurality of antennas 51 _{1 to} 51n, a plurality of signal processing units 852 _{1 to} 852n, and a weight control unit 808.
A plurality of antenna weight multiplication units 553, an antenna signal synthesis unit 554, a serial / parallel conversion unit 56, and a data demodulation unit 5
7, error correction decoding unit 58, information symbol restoration unit 59
With. In addition, the signal processing units 852 _{1 to} 852n include a symbol timing synchronization unit 52a, a guard interval removal unit 52b, a propagation path condition estimation unit 851, a time frequency conversion unit 52c, a spreading code generation unit 52d, and a plurality of spreading units. A code multiplication unit 52e, a plurality of subcarrier weight multiplication units 552f, a plurality of symbol combination units 552g, and a signal power to interference power ratio estimation unit 852 are provided.

[0281] a plurality of antennas ₅₁ 1 _~51n, a plurality of antenna weight multipliers 553, the antenna signal combining unit 55
4, a serial / parallel conversion unit 56, a data demodulation unit 57, an error correction decoding unit 58, an information symbol restoration unit 59, a symbol timing synchronization unit 52a, a guard interval removal unit 52b, and a time frequency conversion unit 52c. , A spread code generator 52d, a plurality of spread code multipliers 52e, a plurality of subcarrier weight multipliers 552f, and a symbol combiner 55.
2g is substantially the same as the receiving device 505 shown in FIG. Therefore, in FIG. 28, the same reference numerals are given and description thereof is omitted.

From the reception of the transmission signal 6 by the plurality of antennas 51 _{1 to} 51n to the removal of the guard interval from the reception signal 7 by the guard interval removing unit 52b,
Processing similar to that of the receiving device 505 shown in FIG. 18 is performed.

The propagation path condition estimation unit 851 estimates the propagation path condition in which the signal transmitted by the transmitting device propagates, that is, the condition of the propagation path between the transmitting device and the receiving device 805.
The channel condition estimation unit 851 estimates the delay spread, the number of paths, the maximum Doppler frequency, etc. as the channel conditions. The channel condition estimation unit 851 uses the plurality of antennas 51 ₁
Provide as many as ~ 51n. In the reception device 805, the signal processing units 852 ₁ to 851 ₁ corresponding to the antennas 51 ₁ to 51 n are included.
852n comprises a channel condition estimation unit 851 receives signal 7 each antenna ₅₁ 1 _~51n received to estimate the channel state having propagated. Propagation path condition estimating unit 851, based on the reception signal 7 that the antennas ₅₁ 1 ～51N received, the antennas ₅₁ 1 reception signal 7 ～51N received to estimate the channel state having propagated. The channel condition estimation unit 851 inputs the estimated value of the channel condition to the weight control unit 808. In addition, the propagation path condition estimation unit 851 uses the received signal 7
To the time-frequency converter 52c.

After the time-frequency converter 52 separates the received signal 7 into the received signals 7 for each subcarrier, the symbol combiner 552g combines the received signals for each subcarrier over the spread code period. , Processing similar to that of the receiving device 505 shown in FIG. 18 is performed.

The signal power-to-interference power ratio estimation unit 852 is an interference condition estimation unit for estimating the interference condition of the received signal 7. The signal power to interference power ratio estimation unit 852 estimates the signal power to interference power ratio (SIR) of the reception signal 7 as the interference situation in the reception signal 7. The signal power-to-interference power ratio estimation unit 852 estimates the signal power-to-interference power ratio of the received signal 7 combined by the symbol combining unit 552g over the spreading code period. Signal power to interference power ratio estimation unit 8
52 is provided by the number of the plurality of antennas 51 _{1 to} 51 n. In the receiving apparatus 805, the signal processing unit ₈₅₂ 1 _~852n corresponding to each antenna ₅₁ 1 _~51n is, the signal power to interference power estimating the signal power to interference power ratio of the received signal 7 each antenna ₅₁ 1 _~51n received The ratio estimation unit 852 is provided.

[0286] signal power to interference power ratio estimating unit 852, based on the reception signal 7 by the antenna ₅₁ 1 _~51n receives, estimates the signal-to-interference power ratio of the received signal 7 by the antenna ₅₁ 1 _~51n received . The signal power to interference power ratio estimation unit 852 inputs the estimated value of the signal power to interference power ratio of the received signal 7 to the weight control unit 808. Further, the signal power to interference power ratio estimation unit 852 inputs the received signal 7 to the antenna weight multiplication unit 553.

Weight control section 808 includes antenna weight control section 881 and subcarrier weight control section 882.
The weight control unit 808 adjusts the antenna weight and the subcarrier weight so that the spread codes of the plurality of information channels # 1 to #n are orthogonal to each other. Weight control section 808 preferably adjusts the antenna weight and the subcarrier weight so that the spread codes of a plurality of information channels # 1 to #n are orthogonal to each other and the signal power to noise power ratio is increased.
The weight control unit 808 adjusts the antenna weight and the subcarrier weight to individually obtain the antenna weight and the subcarrier weight.

The weight control unit 808 has the propagation path condition estimation unit 8
The antenna weight and the subcarrier weight are adjusted based on the estimated value of the channel condition estimated by 51. Further, weight control section 808 adjusts the antenna weight and the subcarrier weight based on the estimated value of the signal power to interference power ratio which is the estimated value of the interference situation estimated by signal power to interference power ratio estimation section 852.

First, the subcarrier weight controller 882
Subcarrier weights are determined using ORC, MRC, EGC, MMSEC, etc. Subcarrier weight controller 882
For this, the subcarrier weight control units 821 to 828 shown in FIG. 11D and FIG. 12 can be used. still,
Subcarrier weight control section 882 preferably determines the subcarrier weight using MMSEC, and particularly preferably uses subcarrier weight control section 826 shown in FIG.

Next, the antenna weight controller 881 determines the antenna weight based on the estimated value of the propagation path condition. Specifically, first, the antenna weight control unit 881 controls the threshold value of the propagation path condition, which serves as a criterion for adjusting the antenna weight and the subcarrier weight. Antenna weight control unit 88
1 is a threshold value of the propagation path condition which is a criterion for adjusting the antenna weight and the subcarrier weight, so that the subcarrier weight which is obtained by multiplying the received signal 7 first is appropriately set as the antenna weight which is multiplied later. A threshold value that serves as a criterion for determining the antenna weight is controlled.

The threshold value of the propagation path condition is such that the antenna weight is determined by using the equal gain combining method or the maximum ratio combining method when the propagation path condition is not good, when the propagation path condition is good. Is preferably controlled such that the antenna weight is proportional to the estimated value of the signal power to interference power ratio. For example, when the delay spread is estimated as the propagation path condition and the estimated value of the delay spread is larger than the threshold value, the antenna weight is determined using the equal gain combining method or the maximum ratio combining method, When the estimated value of the delay spread is less than or equal to the threshold value, the threshold value of the channel condition is controlled so that the antenna weight becomes proportional to the estimated value of the signal power to interference power ratio.

Further, the antenna weight controller 881 sets the threshold value of the propagation path condition to the modulation system of the received signal 7, the spread code period,
It is preferable to perform control based on at least one of the code multiplexing number and other cell interference. Antenna weight controller 881
Acquires the modulation scheme, spreading code period, code multiplexing number or other cell interference from the received signal 7. Other-cell interference refers to the amount of interference with respect to the receiving device 805 from cells other than the cell in which the receiving device 805 is located.

The antenna weight control unit 881 uses the threshold value of the channel condition as the modulation method when using the parameter indicating that the channel condition is better as the parameter indicating the channel condition is smaller like the delay spread. Multi-valued number, spreading code period, code multiplexing number, lower as other cell interference decreases, multi-valued modulation system, spreading code period, code multiplexing number,
Increased as the interference from other cells increases. Therefore, for example, when the modulation method is a method with a small multi-valued number such as QPSK or BPSK, the threshold value of the propagation path condition decreases. On the other hand, when the modulation method is a method with a large multi-valued number such as 16QAM or 64QAM, the threshold value of the channel condition increases. On the contrary, if the larger the parameter of the propagation path condition is, the better the propagation path condition is, the threshold value of the propagation path condition is
The higher the multilevel number of the modulation method, the spreading code period, the code multiplexing number, and the other cell interference, the higher the level, and the higher the modulation system number, the spreading code period, the code multiplexing number, and the other cell interference, the lower the level.

As described above, the antenna weight controller 881
However, by controlling the threshold value of the channel condition, which is the criterion for adjusting the antenna weight and the subcarrier weight, based on the modulation method, spreading code period, code multiplexing number, and other cell interference, the modulation method and spreading code period The antenna weight and the subcarrier weight can be adjusted in consideration of the number of code multiplexes and the interference of other cells.

Next, the antenna weight control unit 881 determines the threshold value of the controlled propagation path condition and the propagation condition of the received signal 7 of each of the antennas 51 _{1 to} 51 n input from the propagation condition estimation unit 851. Compare with the estimated value. The antenna weight controller 881 determines the antenna weight based on the comparison result. For example, the antenna weight controller 881
When the propagation path condition is not good, such as when the estimated value of the delay spread of the received signals 7 of the antennas 51 _{1 to} 51 n is larger than the threshold value, the antenna weights are calculated using the equal gain combining method or the maximum ratio combining method. To decide. For example, as the antenna weight controller 881, the antenna weight controllers 812 and 813 shown in FIGS. 9B and 9C can be used.

[0296] On the other hand, the antenna weight controller 881, as in the case estimate of the delay spread of the received signal 7 of the antenna 51 ₁ ～51N is equal to or less than the threshold, when the propagation condition is good, the antenna 51 ₁ The antenna weight of each antenna 51 _{1 to} 51 n proportional to the estimated value of the signal power to interference power ratio of ˜51 n is determined. The antenna weight control unit 881
The estimated value of the signal power-to-interference power ratio of each antenna 51 _{1 to} 51 n input from the signal power-to-interference power ratio estimation unit 852 is used as the estimated value of the signal power-to-interference power ratio of each antenna 51 _{1 to} 51 n. The antenna weights of the proportional antennas 51 _{1 to} 51 n are determined.

As described above, the weight control unit 808 is such that the antenna weight control unit 881 multiplies the received signal 7 by the subcarrier weight previously determined by the subcarrier weight control unit 882.
The antenna weight to be multiplied by is adjusted based on the estimated value of the propagation path condition and the estimated value of the interference condition such as the signal power to interference power ratio. Accordingly, the weight control unit 808 can adjust the antenna weight and the subcarrier weight based on the estimated value of the propagation path situation and the estimated value of the interference situation.

After that, the antenna weight multiplication unit 553 causes the antennas 51 _{1 to} 51 combined over the spread code period.
The n received signals 7 are multiplied by the antenna weight. The antenna signal combiner 554 combines the received signal 7 multiplied by the antenna weight among the antennas 51 ₁ to 51 n. The received signal 7 synthesized by the antenna signal synthesizer 554 is
It is input to the serial-parallel converter 56. After that, the same processing as that of the receiving device 505 shown in FIG. 18 is performed, and the information symbol is output.

The receiving apparatus 805 replaces the signal power-to-interference power ratio estimating section 852 with the desired signal power-to-interference wave power ratio (C
An interference condition estimation unit that estimates the interference power of (IR) or the received signal 7 may be provided. In this case, the antenna weight control unit 881 uses the estimated value of the desired wave power to the interference wave power ratio of each of the antennas 51 _{1 to} 51 n when the propagation path condition is good as in the case where the estimated value of the delay spread is equal to or less than the threshold value. A proportional antenna weight or an antenna weight proportional to the reciprocal of interference power is determined.

Further, since the receiving apparatus 805 performs space diversity combining after despreading, the subcarrier weight is determined first. When the receiving device performs despreading after spatial diversity combining, the antenna weight control unit,
Determine the antenna weight first. Then, the antenna signal synthesizing unit synthesizes the reception signal 7 multiplied by the antenna weight between the antennas. The signal power to interference power ratio estimation unit 852 is
The signal power to interference power ratio of the reception signal 7 combined between the antennas is estimated. Then, the subcarrier weight control unit
The subcarrier weight to be multiplied by the reception signal 7 multiplied by the antenna weight is adjusted based on the estimated value of the propagation path condition and the estimated value of the signal power to interference power ratio.

Also, the signal power to interference power ratio estimation unit 852
Is not the signal power-to-interference power ratio of the received signal 7 synthesized by the symbol synthesizing unit 552g over the spreading code period, but the reception for each subcarrier before the synthesizing by the symbol synthesizing unit 552g over the spreading code period. The signal power to interference power ratio of signal 7 may be estimated. Alternatively, the signal power-to-interference power ratio estimation unit 852 sets the signal power pair of the received signal 7 after being combined by the symbol combining unit 552g over the spreading code period and the received signal 7 for each subcarrier before being combined. The interference power ratio may be estimated.
Then, weight control section 808 compares the estimated values of the signal power to interference power ratio before and after combining, and controls the antenna weight and the subcarrier weight using the highly accurate estimated value of the signal power to interference power ratio. May be.

Further, in the receiving apparatus 805, the antenna weight control unit 881 uses, as the antenna weight information, the modulation system of the received signal 7, the spreading code period, the code multiplex number, other cell interference,
The estimated value of the propagation path situation and the estimated value of the interference situation are acquired.
Further, when the antenna weight control unit 881 determines the antenna weight using the equal gain combining method or the maximum ratio combining method, as in the receiving device 505 shown in FIG. The antenna weight information is acquired from the received signal 7 for each antenna that has been synthesized over the entire period. Note that the subcarrier weight control unit 882 can acquire the subcarrier weight information in the same manner as the receiving device 505 shown in FIG.

(Communication Method) Next, the case of receiving a received signal using the receiving apparatus 805 shown in FIG. 28 will be described. As shown in FIG. 29, the receiving apparatus 805, the antennas ₅₁ 1 _~51n receives a transmission signal 6 is a multi-carrier CDMA signal (S701). Next, the receiving apparatus 805 based on the received signal 7 each antenna ₅₁ 1 ～51N received, as the propagation path state that the antennas ₅₁ 1 reception signal 7 ～51N received has been propagated, estimates the delay spread (S702). Next, the receiving device 805
Estimates the noise power estimation value, the code multiplexing number estimation value, and the channel estimation value for each subcarrier for the reception signal 7 received by each of the antennas 51 _{1 to} 51 n. Then, the reception device 805 determines the subcarrier weight using MMSEC (S703).

The reception device 805 multiplies the determined subcarrier weight by the received signal 7 for each subcarrier received by the antennas 51 _{1 to} 51 n. Then, the receiving device 805
Synthesizes the received signal 7 over the spread code period (S7).
04). The reception device 805 estimates the signal power-to-interference power ratio of the reception signal 7 combined over the spreading code period (S705). The reception device 805 uses the estimated delay spread and the signal power to interference power ratio to estimate the antenna 5
The antenna weights of 1 _{1 to} 51n are determined (S706).
Specifically, the reception device 805 compares the estimated value of the delay spread with the threshold value of the delay spread. Receiver 80
5 determines the antenna weight by using the equal gain combining method or the maximum ratio combining method when the estimated value of the delay spread is larger than the threshold value. On the other hand, if the estimated value of the delay spread is less than or equal to the threshold value, the receiving device 805 determines the antennas 51 ₁ to
The antenna weight proportional to the estimated value of the signal power to interference power ratio of the received signal 7 of 51n is determined. Finally, the receiving device 8
05 multiplies the received signal 7 for each of the antennas 51 _{1 to} 51 n combined over the spreading code period by the determined antenna weight, and combines the antennas 51 _{1 to} 51 n (S 70).
7). The combined reception signal 7 is input to the serial-parallel converter 56.

[0305] Such a communication system and receiving device 80
5, according to the communication method, almost the same effects as those of the communication system 1, the receiving device 5, and the communication method shown in FIGS. 1, 7, and 14 can be obtained. Further, the channel condition estimation unit 851 estimates the channel condition. Signal power to interference power ratio estimation unit 8
52 estimates the interference situation such as the signal power to interference power ratio of the received signal 7. Then, weight control section 808 adjusts the antenna weight and the subcarrier weight based on the estimated value of the propagation path condition and the estimated value of the interference condition. Therefore, the receiving device 8
05 indicates, depending on the propagation path condition and the interference condition of the received signal 7,
The antenna weight and subcarrier weight can be appropriately determined. Therefore, the receiving device 805 can further improve the signal transmission characteristics. Further, the receiving device 80 that adjusts the antenna weight and the subcarrier weight based on the estimated value of the propagation path condition and the estimated value of the interference condition.
5 can be realized with a relatively simple configuration, the control is simple, and the control delay is small.

[Eighth Embodiment] Next, the eighth embodiment of the present invention will be described.
A communication system and a communication method according to the embodiment will be described. The communication system according to the eighth embodiment includes a receiving device 905 shown in FIG. 30 as a receiving device.

(Reception Device) As shown in FIG. 30, the reception device 905 includes a plurality of antennas 51 _{1 to} 51n, a plurality of signal processing units 952 _{1 to} 952n, and a weight control unit 908.
A plurality of antenna weight multiplication units 553, an antenna signal synthesis unit 554, a serial / parallel conversion unit 56, and a data demodulation unit 5
7, error correction decoding unit 58, information symbol restoration unit 59
With. Further, the signal processing units 952 _{1 to} 952n include a symbol timing synchronization unit 52a, a guard interval removal unit 52b, a time frequency conversion unit 52c, a spread code generation unit 52d, a plurality of spread code multiplication units 52e, and a plurality of spread code multiplication units 52e. A subcarrier weight multiplication unit 552f, a plurality of symbol combination units 552g, and a signal power to interference power ratio estimation unit 852 are provided.

[0308] a plurality of antennas ₅₁ 1 _~51n, a plurality of antenna weight multipliers 553, the antenna signal combining unit 55
4, a serial / parallel conversion unit 56, a data demodulation unit 57, an error correction decoding unit 58, an information symbol restoration unit 59, a symbol timing synchronization unit 52a, a guard interval removal unit 52b, and a time frequency conversion unit 52c. , A spread code generator 52d, a plurality of spread code multipliers 52e, a plurality of subcarrier weight multipliers 552f, and a symbol combiner 55.
2g is substantially the same as the receiving device 505 shown in FIG. Further, the signal power to interference power ratio estimation unit 852 is substantially the same as the reception device 805 shown in FIG. Therefore, in FIG. 30, the same reference numerals are given and description thereof is omitted.

From the reception of the transmission signal 6 by the plurality of antennas 51 _{1 to} 51n until the symbol combining section 552g combines the reception signal 7 over the spreading code period, the reception device 505 shown in FIG. Similar processing is performed. next,
The signal power-to-interference power ratio estimation unit 852 estimates the signal power-to-interference power ratio of the reception signal 7 combined by the symbol combining unit 552g over the spreading code period. The signal power to interference power ratio estimation unit 852 inputs the estimated value of the signal power to interference power ratio of the received signal 7 to the weight control unit 908. or,
The signal power to interference power ratio estimation unit 852 inputs the received signal 7 to the antenna weight multiplication unit 553.

Weight control section 908 includes antenna weight control section 981 and subcarrier weight control section 982.
The weight control unit 908 adjusts the antenna weight and the subcarrier weight so that the spread codes of the plurality of information channels # 1 to #n are orthogonal to each other. Weight control section 908 preferably adjusts the antenna weight and the subcarrier weight such that the spread codes of the plurality of information channels # 1 to #n are orthogonal to each other and the signal power to noise power ratio becomes large.
The weight control unit 908 adjusts the antenna weight and the subcarrier weight to individually obtain the antenna weight and the subcarrier weight.

Weight control section 908 adjusts the antenna weight and subcarrier weight based on the estimated value of the signal power to interference power ratio estimated by signal power to interference power ratio estimation section 852. First, the subcarrier weight control unit 982
Subcarrier weights are determined using C, MRC, EGC, MMSEC, etc. As the subcarrier weight controller 982, the subcarrier weight controllers 821 to 828 shown in FIG. 11D and FIG. 12 can be used. Note that the subcarrier weight control unit 982 preferably determines the subcarrier weight using MMSEC.
It is preferable to use the subcarrier weight controller 826 shown in (e).

Next, the antenna weight controller 981 determines the antenna weight based on the estimated value of the signal power to interference power ratio. Specifically, first, the antenna weight controller 981
Controls the threshold value of the difference in the signal power to interference power ratio between the antennas, which serves as a criterion for adjusting the antenna weight and the subcarrier weight. The antenna weight control unit 981 uses, as a threshold value of the difference in the signal power to interference power ratio between the antennas, which is a criterion for adjusting the antenna weight and the subcarrier weight, with respect to the subcarrier weight previously multiplied by the received signal 7. A threshold serving as a criterion for determining the antenna weight is controlled so that the antenna weight to be multiplied later becomes appropriate.

When the difference in the signal power to interference power ratio between the antennas is small, the threshold value is the antenna weight using the equal gain combining method or the maximum ratio combining method when the difference in the signal power to interference power ratio between the antennas is small. As described above, when the difference in the signal power to interference power ratio between the antennas is large, it is preferable to control the antenna weight so that the antenna weight is proportional to the signal power to interference power ratio.

Further, the antenna weight controller 981 sets the threshold value of the difference in the signal power to interference power ratio between the antennas to the received signal 7
It is preferable to control based on at least one of the modulation method, spreading code period, code multiplexing number, or other cell interference. The antenna weight controller 981 acquires the modulation scheme, spreading code period, code multiplexing number or other cell interference from the received signal 7. The antenna weight control unit 981 lowers the threshold value of the difference between the signal power and the interference power ratio between the antennas as the modulation scheme multi-level number, spreading code period, code multiplex number, and other cell interference are smaller, and the modulation scheme multi-level is The higher the number, the spreading code period, the code multiplexing number, and the interference with other cells, the higher the value.

As described above, the antenna weight controller 981
Control the threshold of the difference in the signal power to interference power ratio between the antennas, which is the criterion for adjusting the antenna weight and the subcarrier weight, based on the modulation method, spreading code period, code multiplexing number, and other cell interference. Thereby, the antenna weight and the subcarrier weight can be adjusted in consideration of the modulation scheme, the spreading code period, the code multiplexing number, and other cell interference.

[0316] Next, the antenna weight controller 981, based on an estimate of the signal power to interference power ratio for each antenna ₅₁ 1 ～51N inputted from the signal power to interference power ratio estimating section 852, the antenna ₅₁ 1 - The difference in signal power to interference power ratio between 51n is calculated. For example, the antenna weight controller 98
1 calculates the difference between the maximum value and the minimum value of the estimated values of the signal power to interference power ratio of the antennas 51 _{1 to} 51 n. Next, the antenna weight controller 981 calculates the threshold value of the difference in the signal power to interference power ratio between the controlled antennas and the calculated antenna 51 _1.
.About.51n and the difference in the estimated value of the signal power to interference power ratio. The antenna weight controller 881 determines the antenna weight based on the comparison result.

The antenna weight control unit 981 determines that the calculated difference in the estimated value of the signal power-to-interference power ratio between the antennas 51 _{1 to} 51n is less than or equal to the threshold value of the difference in the signal power-to-interference power ratio between the antennas. , The equal weight combining method or the maximum ratio combining method is used to determine the antenna weights. On the other hand, if the calculated difference in the estimated value of the signal power to interference power ratio between the antennas 51 _{1 to} 51 n exceeds the threshold of the difference in the signal power to interference power ratio between the antennas, the antenna weight control unit 981 determining an antenna weight for each antenna ₅₁ 1 _~51n proportional to an estimate of the antenna ₅₁ 1 _~51n signal power to interference power ratio.

[0318] For example, the antenna weight controller 981, the difference between the maximum value and the minimum value of the estimated value of the calculated antenna ₅₁ signal power to interference power ratio between 1 ～51N found antennas ₅₁ 1 ~
When the difference between the signal power and the interference power ratio between 51n is less than or equal to the threshold value, the antenna weight is determined by using the equal gain combining method or the maximum ratio combining method. For example, as the antenna weight controller 981, the antenna weight controllers 812 and 813 shown in FIGS. 9B and 9C can be used. On the other hand, the antenna weight control unit 981 calculates the calculated antennas 51 _{1 to} 51 n.
When the difference between the maximum value and the minimum value of the estimated value of the signal power to the interference power ratio between the antennas exceeds the threshold value of the difference of the signal power to the interference power ratio between the antennas, the signal power pair of each of the antennas 51 _{1 to} 51 n. Each antenna 51 _{1 to} 5 proportional to the estimated value of the interference power ratio
Determine the 1n antenna weight.

As described above, the weight control unit 908 is configured such that the antenna weight control unit 981 multiplies the received signal 7 by the subcarrier weight previously determined by the subcarrier weight control unit 982.
The antenna weight to be multiplied by is adjusted based on the estimated value of the signal power to interference power ratio. As a result, the weight control unit 90
8 can adjust the antenna weight and the subcarrier weight based on the estimated value of the signal power to interference power ratio.

After that, the antenna weight multiplication unit 553 causes the antennas 51 _{1 to} 51n synthesized over the spread code period.
Each received signal 7 is multiplied by the antenna weight. The antenna signal combiner 554 combines the received signal 7 multiplied by the antenna weight among the antennas 51 ₁ to 51 n. The reception signal 7 combined by the antenna signal combining unit 554 is input to the serial / parallel conversion unit 56. After that, the same processing as that of the receiving device 505 shown in FIG. 18 is performed, and the information symbol is output.

The reception apparatus 905 replaces the signal power to interference power ratio estimation unit 852 and replaces the desired signal power to the interference wave power ratio (C
An interference condition estimation unit that estimates the interference power of (IR) or the received signal 7 may be provided. In this case, the antenna weight control unit 981 calculates the difference in the desired wave power to the interference wave power ratio between the antennas 51 _{1 to} 51n and the interference power difference. Then, the antenna weight control unit 981 determines that the calculated difference between the desired wave power to the interference wave power ratio between the antennas 51 _{1 to} 51n or the difference between the interference powers is the threshold value of the difference between the desired wave power to the interference wave power ratio between the antennas. Alternatively, if the interference power difference between the antennas is equal to or less than the threshold value, the antenna weight is determined by using the equal gain combining method or the maximum ratio combining method. On the other hand, the antenna weight controller 981
Is the threshold of the difference between the desired wave power to the interference wave power ratio or the difference in the interference power between the calculated desired antenna power to the interference wave between the antennas 51 _{1 to} 51n, or the interference power between the antennas. In the case where the threshold value of the difference is exceeded, the antenna weight proportional to the estimated value of the desired wave power to the interference wave power ratio or the antenna weight proportional to the reciprocal of the interference power is determined.

Further, since the receiving apparatus 905 performs space diversity combining after despreading, the subcarrier weight is determined first. When the receiving device performs despreading after spatial diversity combining, the antenna weight control unit,
Determine the antenna weight first. Then, the antenna signal synthesizing unit synthesizes the reception signal 7 multiplied by the antenna weight between the antennas. The signal power to interference power ratio estimation unit estimates the signal power to interference power ratio of the reception signal 7 combined between the antennas. Then, the subcarrier weight control unit adjusts the subcarrier weight by which the received signal 7 multiplied by the antenna weight is multiplied based on the estimated value of the signal power to interference power ratio.

Also, in the receiving apparatus 905, the antenna weight control section 981 uses as the antenna weight information the modulation scheme of the received signal 7, the spreading code period, the code multiplex number, other cell interference,
Get an estimate of the interference situation. Further, when the antenna weight controller 981 determines the antenna weight using the equal gain combining method or the maximum ratio combining method, the receiving device 5 shown in FIG.
Similar to 05, antenna weight information is acquired from the reception signal 7 for each antenna that is combined by the symbol combining unit 552g over the spread code period. The subcarrier weight control unit 982 can acquire the subcarrier weight information in the same way as the receiving device 505 shown in FIG.

(Communication Method) Next, the case of receiving a received signal using the receiving apparatus 905 shown in FIG. 30 will be described. As shown in FIG. 31, the receiving device 905 performs steps (S801) to (S804). Step (S8
01) to (S804) are steps (S) shown in FIG.
701) and (S703) to (S705).

Next, the receiving apparatus 905 uses the estimated value of the estimated signal power-to-interference power ratio for each of the antennas 51 ₁ ...
The antenna weight of 51n is determined (S805). Specifically, the reception device 905 compares the threshold value of the difference in the signal power to interference power ratio between the antennas with the difference in the estimated value of the signal power to interference power ratio between the antennas 51 _{1 to} 51n. When the difference in the estimated value of the signal power to interference power ratio between the antennas is equal to or less than the threshold value, receiving apparatus 905 determines the antenna weight using the equal gain combining method or the maximum ratio combining method. On the other hand, if the difference in the estimated value of the signal power-to-interference power ratio between the antennas exceeds the threshold, the receiving device 905 receives each of the antennas 51 _{1 to} 51 _1.
The antenna weight of each of the antennas 51 _{1 to} 51 n proportional to the estimated value of the signal power to interference power ratio of the n received signals 7 is determined. Finally, the receiving device 905 combines the determined antenna weights with the antennas 51 ₁ to 51 ₁ that are combined over the spreading code period.
The reception signal 7 for each 51n is multiplied to obtain the antennas 51 _{1 to} 51.
It synthesize | combines between n (S806).

[0326] Such a communication system and receiving device 90
5, according to the communication method, almost the same effects as those of the communication system 1, the receiving device 5, and the communication method shown in FIGS. 1, 7, and 14 can be obtained. Further, the signal power to interference power ratio estimation unit 852 estimates the signal power to interference power ratio of the received signal 7. Then, weight control section 908 adjusts the antenna weight and the subcarrier weight based on the estimated value of the signal power to interference power ratio. Therefore, the receiving apparatus 905 can appropriately determine the antenna weight and the subcarrier weight according to the interference situation of the received signal 7. Therefore, the receiving device 805 can further improve the signal transmission characteristics. Moreover, the receiving apparatus 905 adjusts the antenna weight and the subcarrier weight using the estimated value of the signal power to interference power ratio of the received signal 7 that is combined over the spread code period, so that the adjustment can be performed accurately. . Further, the receiving apparatus 905 that adjusts the antenna weight and the subcarrier weight based on such an estimated value of the interference situation can be realized with a relatively simple configuration, the control is simple, and the control delay is small.

[Ninth Embodiment] Next, a ninth embodiment of the present invention will be described.
A communication system and a communication method according to the embodiment will be described. The communication system according to the ninth embodiment includes a receiving device 105 shown in FIG. 32 as a receiving device.

(Reception Device) As shown in FIG. 32, the reception device 105 includes a plurality of antennas 51 _{1 to} 51 n, a plurality of signal processing units 952 _{1 to} 952 n, and a weight control unit 108.
A plurality of antenna weight multiplication units 553, an antenna signal synthesis unit 554, a serial / parallel conversion unit 56, and a data demodulation unit 5
7, error correction decoding unit 58, information symbol restoration unit 59
And a reception quality measuring unit 151. In addition, the signal processing units 152 _{1 to} 152 n include the symbol timing synchronization unit 52.
a, a guard interval removal unit 52b, a time frequency conversion unit 52c, a spread code generation unit 52d, a plurality of spread code multiplication units 52e, and a plurality of subcarrier weight multiplication units 5
52 f, a plurality of symbol combining units 552 g, and a signal power to interference power ratio estimating unit 852.

[0329] a plurality of antennas ₅₁ 1 _~51n, a plurality of antenna weight multipliers 553, the antenna signal combining unit 55
4, a serial / parallel conversion unit 56, a data demodulation unit 57, an error correction decoding unit 58, an information symbol restoration unit 59, a symbol timing synchronization unit 52a, a guard interval removal unit 52b, and a time frequency conversion unit 52c. , A spread code generator 52d, a plurality of spread code multipliers 52e, a plurality of subcarrier weight multipliers 552f, and a symbol combiner 55.
2g is substantially the same as the receiving device 505 shown in FIG. Further, the signal power to interference power ratio estimation unit 852 is substantially the same as the reception device 805 shown in FIG. Therefore, in FIG. 32, the same reference numerals are given and the description thereof is omitted.

From the reception of the transmission signal 6 by the plurality of antennas 51 _{1 to} 51n until the symbol combining section 552g combines the reception signal 7 over the spreading code period, the reception device 505 shown in FIG. Similar processing is performed. next,
The signal power-to-interference power ratio estimation unit 852 estimates the signal power-to-interference power ratio of the reception signal 7 combined by the symbol combining unit 552g over the spreading code period, and calculates the signal power-to-interference power ratio of the reception signal 7. The estimated value is input to the weight control unit 108. Further, the signal power to interference power ratio estimation unit 852 inputs the received signal 7 to the antenna weight multiplication unit 553.

After that, the antenna weight multiplication unit 553 causes the antennas 51 _{1 to} 51 n combined over the spreading code period.
Each received signal 7 is multiplied by the antenna weight. The antenna signal combiner 554 combines the received signal 7 multiplied by the antenna weight among the antennas 51 ₁ to 51 n. The reception signal 7 combined by the antenna signal combining unit 554 is input to the serial / parallel conversion unit 56. Then, up to the information symbol restoration unit 59, the same processing as the reception device 505 shown in FIG. 18 is performed. The information symbol restoration unit 59 restores the information symbol that has been subjected to the error correction decoding processing to a state in which it can be output to the output device, and inputs it to the reception quality measurement unit 151.

Reception quality measuring section 151 measures the reception quality of the information symbol restored from received signal 7. The reception quality measuring unit 151 determines the reception quality of the information symbol as a bit error rate (BER) of the information symbol.
And frame error rate (FER). Reception quality measuring section 151 inputs the measured value of the information symbol to weight control section 108. Also, reception quality measuring section 151 outputs information symbols.

Weight control section 108 includes antenna weight control section 181 and subcarrier weight control section 182.
The weight control unit 108 adjusts the antenna weight and the subcarrier weight so that the spreading codes of the plurality of information channels # 1 to #n are orthogonal to each other. Weight control section 108 preferably adjusts the antenna weight and the subcarrier weight so that the spread codes of the plurality of information channels # 1 to #n are orthogonal to each other and the signal power to noise power ratio becomes large.
The weight control unit 108 adjusts the antenna weight and the subcarrier weight to individually obtain the antenna weight and the subcarrier weight.

Weight control section 108 has reception quality measuring section 15
1 adjusts the antenna weight and the subcarrier weight based on the measured value of the reception quality measured by 1. Further, weight control section 108 adjusts the antenna weight and the subcarrier weight based on the estimated value of the signal power to interference power ratio estimated by signal power to interference power ratio estimation section 852.

First, the subcarrier weight controller 182
Subcarrier weights are determined using ORC, MRC, EGC, MMSEC, etc. Subcarrier weight controller 182
For this, the subcarrier weight control units 821 to 828 shown in FIG. 11D and FIG. 12 can be used. still,
Subcarrier weight control section 182 preferably determines the subcarrier weight using MMSEC, and particularly preferably uses subcarrier weight control section 826 shown in FIG.

Next, antenna weight control section 181 determines the antenna weight based on the measured value of reception quality. Specifically, first, the antenna weight controller 181 controls the threshold value of the variation amount of the reception quality, which serves as a criterion for adjusting the antenna weight and the subcarrier weight. The antenna weight control unit 181 uses, as a threshold value of the variation amount of the reception quality, which serves as a criterion for adjusting the antenna weight and the subcarrier weight, the subcarrier weight obtained by multiplying the received signal 7 first and the antenna weight obtained later. Is controlled so that the antenna weight becomes appropriate.

[0337] The threshold value of the variation amount of the reception quality is different from the previously determined antenna weight when the increase amount of the reception quality is large, when the increase amount of the reception quality indicates that the reception quality is worse. When the amount of increase in reception quality is small so that the antenna weight can be determined,
It is preferably controlled so that the same antenna weight as the previously determined antenna weight can be determined. For example, when a bit error rate or a frame error rate is measured as the reception quality and an increase amount of the bit error rate or the frame error rate is larger than a threshold value, an antenna weight different from the previously determined antenna weight can be determined. As described above, when the increase amount of the bit error rate or the frame error rate is equal to or less than the threshold value, the same antenna weight as the previously determined antenna weight can be determined. On the contrary, the threshold of the variation amount of the reception quality indicates that the larger the reduction amount of the reception quality is, the worse the reception quality is. It is preferable that when the reception quality decrease amount is small so that different antenna weights can be determined, the same antenna weight as the previously determined antenna weight can be determined.

Further, the antenna weight control section 181 can control the threshold value of the variation amount of the reception quality based on at least one of the modulation system of the received signal 7, the spreading code period, the code multiplex number or other cell interference. preferable. The antenna weight control unit 181 acquires the modulation scheme, spreading code period, code multiplexing number or other cell interference from the received signal 7. The antenna weight control unit 181 modulates the threshold value of the increase amount of the reception quality when it indicates that the reception quality deteriorates as the increase amount of the reception quality increases like the bit error rate and the frame error rate. System multi-valued number, spread code period, code multiplex number,
It decreases as the other cell interference decreases, and increases as the modulation scheme multilevel number, spreading code period, code multiplexing number, and other cell interference increase. On the contrary, when the reception quality is deteriorated as the decrease amount of the reception quality is large, the antenna weight control unit 181 sets the threshold value of the reception quality decrease amount to the multi-value number of the modulation method and the spread method. The smaller the code period, the code multiplexing number, and the other cell interference, the lower the value.

As described above, the antenna weight controller 181
However, by controlling the threshold value of the fluctuation amount of the reception quality, which is a criterion for adjusting the antenna weight and the subcarrier weight, based on the modulation method, spreading code period, code multiplexing number, and other cell interference, The antenna weight and the subcarrier weight can be adjusted in consideration of the code period, the code multiplexing number, and other cell interference. Further, the antenna weight control unit 181 holds the reference value of the reception quality for determining whether to maintain the antenna weight determined last time. The reference value of reception quality can be set, for example, based on the required reception quality.

Next, antenna weight control section 181 compares the reference value of reception quality with the measurement value of reception quality of the information symbol input from reception quality measurement section 151. When the measured value of reception quality satisfies the reference value of reception quality, the antenna weight control unit 181 determines the antenna weight to be the same as the antenna weight determined last time. on the other hand,
The antenna weight control unit 181 calculates the variation amount of the measured value of the reception quality when the measured value of the reception quality does not satisfy the reference value of the received quality. The antenna weight control unit 181 holds the previous measurement value of the reception quality and calculates the difference from the measurement value of the reception quality newly input from the reception quality measurement unit 151.

Next, antenna weight control section 181 compares the controlled threshold value of the variation amount of the reception quality with the variation amount of the calculated measured value of the reception quality. Antenna weight controller 181
Determines the antenna weight based on the comparison result. The antenna weight control unit 181 sets an antenna weight different from the previously determined antenna weight when the increase amount of the measurement value of the reception quality such as the bit error rate or the frame error rate is larger than the threshold value of the variation amount of the reception quality. decide. For example, when the antenna weights are determined by using the equal gain combining method or the maximum ratio combining method last time, the antenna weight control unit 181 causes the antenna powers of the antennas 51 ₁ to The 51n signal power to interference power ratio estimate is used to determine an antenna weight that is proportional to the signal power to interference power ratio estimate. Further, when the antenna weight proportional to the estimated value of the signal power to interference power ratio is determined last time, the antenna weight controller 181 determines the antenna weight using the equal gain combining method or the maximum ratio combining method.

On the other hand, if the increase amount of the measured value of the reception quality such as the bit error rate or the frame error rate is less than or equal to the threshold value of the variation amount of the reception quality, the antenna weight control unit 181 determines that the antenna weight is the previously determined antenna weight. Determine the same antenna weight. For example, when the antenna weight is determined by using the equal gain combining method or the maximum ratio combining method last time, the antenna weight control unit 1
81 determines the antenna weight using the equal gain combining method or the maximum ratio combining method. In addition, when the antenna weight proportional to the estimated value of the signal power to interference power ratio is determined last time, the antenna weight control unit 181 causes the antenna power control unit 181 to input each of the antennas 51 ₁ to 511 input from the signal power to interference power ratio estimation unit 852. The 51n signal power to interference power ratio estimate is used to determine an antenna weight that is proportional to the signal power to interference power ratio estimate.

As described above, the weight control unit 108 has the antenna weight control unit 181 multiplying the received signal 7 by the subcarrier weight previously determined by the subcarrier weight control unit 182.
The antenna weight to be multiplied by is adjusted based on the measured value of the reception quality of the information symbol and the estimated value of the signal power to interference power ratio. By this means, weight control section 108 can adjust the antenna weight and subcarrier weight based on the measured value of the reception quality of information symbols and the estimated value of the signal power to interference power ratio.

The receiving apparatus 105 replaces the signal power-to-interference power ratio estimating unit 852 with the interference status of the received signal 7 as the desired signal power-to-interference wave power ratio of the received signal 7 and the interference power of the received signal 7. It may be possible to provide an interference situation estimation unit for estimating In this case, the antenna weight controller 18
1 determines the antenna weight proportional to the estimated value of the desired wave power to the interference wave power ratio and the antenna weight proportional to the reciprocal of the interference power.

Further, since receiving apparatus 105 carries out spatial diversity combining after despreading, subcarrier weights are decided first. When the receiving device performs despreading after spatial diversity combining, the antenna weight control unit,
Determine the antenna weight first. Then, the antenna signal synthesizing unit synthesizes the reception signal 7 multiplied by the antenna weight between the antennas. The signal power to interference power ratio estimation unit 852 is
The signal power to interference power ratio of the reception signal 7 combined between the antennas is estimated. Then, the subcarrier weight control unit
The subcarrier weight to be multiplied by the received signal 7 multiplied by the antenna weight is adjusted based on the measured value of the reception quality of the information symbol and the estimated value of the signal power to interference power ratio.

Further, in the receiving apparatus 105, the antenna weight control section 181 uses the antenna weight information as the modulation method of the received signal 7, the spreading code period, the code multiplexing number, the interference of other cells,
The estimated value of the interference situation and the reception quality of the information symbol are acquired. Further, when the antenna weight control unit 181 determines the antenna weight using the equal gain combining method or the maximum ratio combining method, as in the receiving device 505 shown in FIG. The antenna weight information is acquired from the received signal 7 for each antenna that has been synthesized over the entire period. The subcarrier weight controller 182 is
Subcarrier weight information can be acquired in the same manner as the receiving device 505 shown in FIG.

(Communication Method) Next, the case of receiving a received signal using the receiving apparatus 105 shown in FIG. 32 will be described. As shown in FIG. 33, the reception device 105 performs steps (S901) to (S904). Step (S9
01) to (S904) are steps (S) shown in FIG.
Substantially the same as 801) to (S804).

Next, the receiving apparatus 105 uses the measured value of the reception quality such as the bit error rate of the information symbol and the frame error rate and the estimated value of the signal power to interference power ratio, and the antenna 5
The antenna weight is determined for each of 1 _{1 to} 51n (S90).
5). Specifically, receiving apparatus 105 compares the reference value of reception quality with the measured value of reception quality of information symbols.
When the measurement value of the reception quality satisfies the reference value of the reception quality, receiving apparatus 105 determines the antenna weight to be the same antenna weight as the previously determined antenna weight. On the other hand, if the measurement value of reception quality does not satisfy the reference value of reception quality, receiving apparatus 105 compares the threshold value of the fluctuation amount of reception quality with the fluctuation amount of the measurement value of reception quality.

When the increase amount of the measured value of the reception quality such as the bit error rate or the frame error rate is larger than the threshold value of the variation amount of the reception quality, the receiving apparatus 105 has an antenna weight different from the previously determined antenna weight. To decide. On the other hand, when the increase amount of the measured value of the reception quality such as the bit error rate or the frame error rate is less than or equal to the threshold value of the variation amount of the reception quality, the antenna weight control unit 181 determines the same antenna weight as the previously determined antenna weight. To decide.

Then, the receiving apparatus 105 multiplies the determined antenna weight by the received signal 7 for each of the antennas 51 _{1 to} 51 n combined over the spread code period, and the antenna 51
Synthesized between _{1 ~51n} (S906). Finally, the receiving apparatus 105 measures the reception quality of the information symbol restored by despreading (S907). Step (S907)
The measurement value of the reception quality measured in step S9 is
In 05), it is used when determining the next antenna weight.

[0351] Such a communication system and receiving device 10
5, according to the communication method, almost the same effects as those of the communication system 1, the receiving device 5, and the communication method shown in FIGS. 1, 7, and 14 can be obtained. Furthermore, the reception quality measuring unit 151
The reception quality of the restored information symbol is measured. Further, the signal power to interference power ratio estimation unit 852 estimates the signal power to interference power ratio of the received signal 7. Then, the weight control unit 108
Adjusts the antenna weight and the subcarrier weight based on the measured value of the reception quality of the information symbol and the estimated value of the signal power to interference power ratio. Therefore, receiving apparatus 105 can appropriately determine the antenna weight and the subcarrier weight according to the reception quality of the information symbol and the interference situation such as the signal power to interference power ratio of received signal 7. In particular,
The receiving apparatus 105 can feed back the received quality of the restored information symbol to the antenna weight and the subcarrier weight. Therefore, the receiving device 805 can further improve the signal transmission characteristics.

[Tenth Embodiment] Next, referring to FIG. 7 and FIG.
A simulation performed using the receiving devices 5 and 505 shown in FIG. 8 will be described. The simulation is shown in Figure 7.
Despreading is performed after spatial diversity combining using the receiving apparatus 5 shown in FIG. Space diversity combining is performed by the maximum ratio combining method (hereinafter referred to as "MRC"), and despreading is performed by MMS.
EC, EGC, and ORC are performed in three ways (hereinafter, respectively,
MRC (diversity) / MMSEC (despreading), MR
C (diversity) / EGC (inverse diffusion), MRC (diversity) / ORC (inverse diffusion)). In addition, spatial diversity combining is an equal gain combining method (hereinafter referred to as "EGC").
And the despreading is performed in two ways, MMSEC and EGC (hereinafter, EGC (diversity) / MMSE, respectively).
C (Despread), EGC (Diversity) / EGC (Despread)). In the simulation, the receiver 505 shown in FIG. 18 is used to perform space diversity combining after despreading. Despreading is performed by MMSEC, and spatial diversity combining is performed by EGC (hereinafter, MMSEC).
(Reverse diffusion) / EGC (diversity)). Further, for comparison, despreading is simply performed using MMSEC and EGC. The simulation conditions are diffusion rate SF = 32,
Total number of paths L = 24, delay spread σ = 0.29 (μse
c)

FIG. 34 shows the average packet error rate characteristics with respect to the average reception E _b / N ₀ (signal power to noise power density ratio per information bit) when the code multiplexing number Cmux = 8. As shown in FIG. 34, the receiving device 5 shown in FIG.
05, despreading is performed by MMSEC, and then spatial diversity combining is performed by EGC.
The best characteristics of (inverse diffusion) / EGC (diversity) can be realized. Thus, according to the receiving device 505,
By applying despreading using MMSEC for each antenna, inter-code interference due to the break of orthogonality of spreading codes can be independently reduced for each antenna. Further, in the space diversity combining in the latter stage, it is possible to realize combining that reflects the difference in inter-code interference between antennas.

Further, as compared with the case where despreading is simply performed by MMSEC and EGC, MRC (diversity) / MMS
EC (Despread), MRC (Diversity) / EGC (Despread), MRC (Diversity) / ORC (Despread),
EGC (diversity) / MMSEC (despreading), EG
Good characteristics are shown in any of C (diversity) / EGC (inverse diffusion).

Next, FIG. 35 shows the required average reception E _b / N ₀ characteristics for each antenna satisfying the average packet error rate = 10 ⁻² with respect to the code multiplexing number Cmux. As shown in FIG. 35, using reception apparatus 505 shown in FIG. 18, despreading is performed by MMSEC, and thereafter spatial diversity combining is performed by EMSEC (despreading) / EG.
With C (diversity), even if the delay spread is large, excellent characteristics can be realized regardless of the code multiplexing number. In addition, E that performs despreading after space diversity combining
GC (diversity) / EGC (despreading) and EGC (diversity) / MMSEC (despreading) also show relatively good characteristics.

In the region of Cmux <8 where the number of code multiplexes is small, MRC (diversity) / despreading after space diversity combining is performed using the receiver 5 shown in FIG.
EGC (inverse diffusion) shows good characteristics. As described above, in the case where the receiving device 5 is used, in a region where the influence of inter-code interference is small, MRC having a large diversity gain is used for diversity combining, and despreading considers fluctuations in noise power for each subcarrier due to MRC. It is preferable to use EGC which is not necessary.

Further, FIG. 36 shows the required average reception E _b / N ₀ characteristics satisfying the average packet error rate = 10 ⁻² with respect to the spreading rate. FIG. 36 shows the characteristics when the code multiplex number Cmux / SF = 0.25 normalized by the spreading factor. Fig. 36
18, the receiving apparatus 505 shown in FIG. 18 is used to perform despreading by MMSEC, and then perform spatial diversity combining by EGC (despreading).
In / EGC (diversity), excellent characteristics can be realized regardless of the diffusivity. As described above, when the code multiplexing number is smaller than the spreading factor, the MM that reflects the difference in inter-code interference between the antennas performed using the receiving apparatus 505 is reflected.
The characteristic improvement effect by SEC (Despreading) / EGC (Diversity) is great.

Further, FIG. 37 shows required average reception E _b / N ₀ characteristics satisfying the average packet error rate = 10 ⁻² with respect to fading correlation coefficient between antennas. FIG. 37 shows the characteristics when the code multiplexing number Cmux = 8. As shown in FIG. 37, using receiving apparatus 505 shown in FIG. 18, despreading is performed by MMSEC, and then spatial diversity combining is performed by EGC. MMSEC (despreading) / EGC
With (diversity), good characteristics can be realized when the correlation coefficient is low.

[Modification] The present invention is based on the above first to first aspects.
The present invention is not limited to the zero embodiment, and various modifications can be made. For example, as shown in FIG. 38, the transmission device includes a code multiplex number information generation unit 41i and an information generation unit 41.
j may be provided. The code multiplexing number information generation unit 41i generates information on the code multiplexing number corresponding to the number of information channels # 1 to #n to be code-multiplexed (hereinafter referred to as "code multiplexing number information"), and the information symbol generation unit 4i.
Input to 1a.

The information generating section 41j generates information other than the code multiplex number information, that is, information such as image data and audio to be transmitted to the terminal device, and inputs it to the information symbol generating section 41a. The information symbol generation unit 41a includes an information symbol including both information based on the code multiplex number information input from the code multiplex number information generation unit 41i and the information other than the code multiplex number information input from the information generation unit 41j. To generate. The transmitter transmits an information signal including the code multiplexing number information to the receiver.

Therefore, the receiving apparatus can acquire the code multiplexing number information from the information signal included in the received signal 7. Therefore, the subcarrier weight controllers 826 and 829 shown in FIG. 12E and FIG. 25 do not need the process of estimating the code multiplexing number, and the code multiplexing number estimating units 826c and 829c.
Is unnecessary, the processing and the configuration can be simplified. Further, the subcarrier weight control units 826 and 829 can obtain the subcarrier weight by using not the estimated value but the accurate actual value as the code multiplexing number. Therefore, the subcarrier weight control units 826 and 829 can obtain a more appropriate subcarrier weight.

Further, as shown in FIG. 39, the receiving apparatus may be provided with a plurality of adding units 52g. Each spread code multiplication unit 52e inputs the received signal 7 for each subcarrier multiplied by the spread code to the addition unit 52g. here,
The received signals 7 for each subcarrier input to each addition unit 52g are # 1 to #n (n is a natural number).
Each adder 52g adds the input received signals 7 for each subcarrier from # 1 to #n and averages them in the frequency direction. The addition unit 52g inputs the added reception signal 7 to the antenna weight multiplication unit 52f and the like. Each addition unit 52g
The number of reception signals 7 input to each subcarrier may be changed for each addition unit 52g.

As described above, the adder 52g adds the received signals 7 after the spread code multiplier 52e has multiplied the spread code, and averages them in the frequency direction. Therefore, the addition unit 52g
After adding the received signal 7 and averaging in the frequency direction,
The antenna weight multiplication unit, the subcarrier weight multiplication unit, and the collective weight multiplication unit can multiply the received signal 7 by the antenna weight, the subcarrier weight, and the collective weight. Therefore, the weight control unit determines the antenna weight and the subcarrier weight to be determined,
The number of collective weights can be reduced, and the processing load for weighting can be reduced. Further, since the number of antenna weight multiplication units, subcarrier weight multiplication units, and collective weight multiplication units can be reduced, the configuration of the receiving apparatus can be simplified. In particular,
As a subcarrier weight controller, FIG.
(G), subcarrier weight controller 827 shown in FIG.
, 829, and when the subcarrier weight is obtained using the adaptive algorithm, the weight control unit 308 has the configuration, and the weight update units 827c, 828d, 828d, The amount of calculation performed by 829 g increases. Therefore, the number of subcarrier weights to be determined is reduced, so that the weight update units 827c and 828 are
The amount of calculation performed by d, 829g can be reduced, and the load can be reduced.

Further, as shown in FIG. 40, the receiving apparatus may be provided with a plurality of delay devices 52h and a plurality of adding sections 52i. Each spreading code multiplication unit 52e delays the received signal 7 for each subcarrier multiplied by the spreading code by the delay unit 52.
It is input to h as well as to the addition unit 52i. The plurality of delay devices 52h generate m−1 reception signals 7 for each subcarrier, which are shifted in time, in order to add m input signals 7 for each subcarrier in the time axis direction. Is a natural number). The remaining one is the received signal 7 for each subcarrier directly input from the spread code multiplication unit 52e.
To use. Therefore, m-1 delay devices 52h are provided. Each delay device 52h delays the input reception signal 7 by a predetermined delay time (Ts), inputs it to the next delay device 52h, and inputs it to the addition unit 52i. The delay time (Ts) is set to one symbol length.

Adder 52i adds the received signals 7 for each of a plurality of (m) subcarriers having different times, in the time axis direction, and averages them in the time axis direction. Adder 52
i is the weighted reception signal 7 obtained by adding the antenna weight multiplication unit 52
Enter in f, etc. The number of received signals 7 for each subcarrier input to each adder 52i may be changed for each adder 52i.

According to this, the received signals 7 for each subcarrier are averaged in the time axis direction, and the averaged received signals 7 are combined over the spreading code period and despread. The signal power-to-noise power ratio of the obtained received signal 7 can be increased. Particularly, when the subcarrier weight control units 827 to 829 shown in FIGS. 12F, 12G, and 26 are provided as the subcarrier weight control unit and the subcarrier weight is determined using the adaptive algorithm, the weight control is performed. When the configuration is provided in unit 308, the signal power-to-noise power ratio of despread reception signal 7 used when determining the subcarrier weight becomes large. Therefore, the accuracy and speed of obtaining the subcarrier weight can be improved.

Also, the receiving apparatus has a subcarrier weight control unit 830 and a subcarrier weight multiplication unit 5 shown in FIG. 41 as subcarrier weight control units and subcarrier weight multiplication units.
2j may be used. Further, as the weight control unit, one having the configuration of the subcarrier weight control unit 830 may be used, and as the collective weight multiplication unit, one that multiplies the collective weight at the position of the subcarrier weight multiplication unit 52j may be used.

Subcarrier weight control section 830 has bit string holding section 830a, reference symbol generating section 830b, and
A plurality of symbol duplication units 830c and spreading code multiplication unit 83
0d, frequency / time conversion unit 830e, and error estimation unit 83
0f and the weight update part 830g are provided. The bit string holding unit 830a and the reference symbol generation unit 830b are shown in FIG.
It is substantially the same as the bit string holding unit 825b and the reference symbol generation unit 825c of the subcarrier weight control unit 825 shown in (d).

The reference symbol generator 830b inputs the generated reference symbol to the symbol replicator 830c.
The symbol duplication unit 830c duplicates the reference symbols by the number equal to the spreading code period of the spreading code. Spread code multiplication unit 8
30d multiplies the duplicated reference symbol by a spreading code to obtain a reference signal. The frequency-time conversion unit 830e frequency-time converts the reference signal and spreads the reference signal to a plurality of subcarriers (hereinafter referred to as “reference multicarrier CDM”).
A signal ”). Frequency time conversion unit 830
e is the reference multicarrier CDM to the error estimation unit 830f.
Input the A signal.

The subcarrier weight multiplication unit 52j is provided before the time frequency conversion unit 52c. The subcarrier weight multiplication unit 52j multiplies the received signal 7 by the subcarrier weight. The sub-carrier weight multiplication unit 52j calculates the received signal 7 multiplied by the sub-carrier weight, and the error estimation unit 830.
f and the time-frequency converter 52c. The error estimation unit 830f estimates the error between the reference multi-carrier CDMA signal and the received signal 7 that has not been subjected to the time frequency conversion processing by the time frequency conversion unit 52c by being multiplied by the subcarrier weight. The weight updating unit 830g includes an error estimating unit 83.
The mean square error of the error between the received signal 7 before being subjected to the time frequency conversion processing by the time frequency conversion unit 52c and the reference multicarrier CDMA signal is minimized by being multiplied by the subcarrier weight inputted from 0f. Then, the weights that are sequentially updated are obtained using an adaptive algorithm. The subcarrier weight controller 830 inputs the obtained subcarrier weight 830h to the subcarrier weight multiplier 52j.

According to this, the received signal 7 before the time frequency conversion processing by the time frequency conversion unit 52c is performed,
The subcarrier weights can be updated so that the mean square error with the transmission signal 6 is minimized. As a result, the subcarrier weight control unit 830 is equivalent to updating the subcarrier weights so that the mean square error between the despread reception signal 7 and the transmission signal 6 is minimized. The effect is obtained.

[0372]

According to the present invention, a multi-carrier CDM
Appropriately applying spatial diversity combining to the A transmission system,
The influence of interference between information channels can be reduced and the signal transmission characteristics can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a communication system according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a transmission apparatus according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a transmission signal according to the first embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of another transmission device according to the first embodiment of the present invention.

FIG. 5 is a diagram showing switching of symbols to be input according to the first embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of another transmitting apparatus according to the first embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration of a receiving device according to the first embodiment of the present invention.

FIG. 8 is a diagram showing a case where space diversity combining is simply applied to a multicarrier CDMA transmission system.

FIG. 9 is a block diagram showing a configuration of an antenna weight control unit according to the first embodiment of the present invention.

FIG. 10 is a block diagram showing a configuration of another receiving device according to the first embodiment of the present invention.

FIG. 11 is a diagram illustrating a method of determining a subcarrier weight according to the first embodiment of the present invention.

FIG. 12 is a block diagram showing a configuration of a subcarrier weight control unit according to the first embodiment of the present invention.

FIG. 13 is a flowchart showing a procedure for transmitting a transmission signal according to the first embodiment of the present invention.

FIG. 14 is a flowchart showing a procedure when receiving a reception signal according to the first embodiment of the present invention.

FIG. 15 is a block diagram showing a configuration of a receiving device according to a second embodiment of the present invention.

FIG. 16 is a block diagram showing the configuration of another weight control unit according to the second embodiment of the present invention.

FIG. 17 is a flowchart showing a procedure for receiving a reception signal according to the second embodiment of the present invention.

FIG. 18 is a block diagram showing a configuration of a receiving device according to a third embodiment of the present invention.

FIG. 19 is a flowchart showing a procedure for receiving a reception signal according to the third embodiment of the present invention.

FIG. 20 is a block diagram showing a configuration of a receiving device according to a fourth embodiment of the present invention.

FIG. 21 is a flowchart showing a procedure for receiving a reception signal according to the fourth embodiment of the present invention.

FIG. 22 is a block diagram showing a configuration of a transmission device according to a fifth embodiment of the present invention.

FIG. 23 is a diagram showing a transmission signal according to the fifth embodiment of the present invention.

FIG. 24 is a block diagram showing the configuration of another transmitting apparatus according to the fifth embodiment of the present invention.

FIG. 25 is a block diagram showing a configuration of a subcarrier weight controller according to the fifth embodiment of the present invention.

FIG. 26 is a block diagram showing a configuration of a receiving device according to a sixth embodiment of the present invention.

FIG. 27 is a flowchart showing a procedure for receiving a received signal according to the sixth embodiment of the present invention.

FIG. 28 is a block diagram showing a configuration of a receiving device according to a seventh embodiment of the present invention.

FIG. 29 is a flowchart showing a procedure for receiving a reception signal according to the seventh embodiment of the present invention.

FIG. 30 is a block diagram showing a configuration of a receiving device according to an eighth embodiment of the present invention.

FIG. 31 is a flowchart showing a procedure for receiving a received signal according to the eighth embodiment of the present invention.

FIG. 32 is a block diagram showing a configuration of a receiving device according to a ninth embodiment of the present invention.

FIG. 33 is a flowchart showing a procedure for receiving a received signal according to the ninth embodiment of the present invention.

FIG. 34 is a graph showing average packet error rate characteristics by simulation according to the tenth embodiment of the present invention.

FIG. 35 is a graph showing a characteristic with respect to the code multiplex number by the simulation according to the tenth embodiment of the present invention.

FIG. 36 is a graph showing characteristics with respect to diffusion rate by simulation according to the tenth embodiment of the present invention.

FIG. 37 is a graph showing characteristics with respect to correlation coefficient by simulation according to the tenth embodiment of the present invention.

FIG. 38 is a diagram showing a code multiplex number information generation unit and an information generation unit according to a modified example of the present invention.

FIG. 39 is a diagram showing a process of averaging received signals in the frequency axis direction according to a modification of the present invention.

FIG. 40 is a diagram showing a process of averaging received signals in the time axis direction according to a modification of the present invention.

FIG. 41 is a block diagram showing configurations of a subcarrier weight control unit and a subcarrier weight multiplication unit according to a modification of the present invention.

FIG. 42 is a diagram showing a conventional multicarrier CDMA transmission system.

[Explanation of symbols]

1 communication system 2 base stations 3 terminal devices 4,204,304,404,504 Transmission device 5,105,205,305,505,605,70
5,805,905 receiver 8, 108, 308, 408, 508, 608, 70
8,808,908 Weight control unit 41₁, 41n, 241₁, 241n, 341₁, 34
1n, 441₁, 441n, 541₁, 541n signal
Processing unit 41a Information symbol generator 41b Error correction coding unit 41c data modulator 41d, 241d serial-parallel converter 41e Spreading code generator 41f, 241f, 830c Symbol duplicator 41g, 241g, 341g, 830d Spread code multiplication
Department 41h, 241h, 341h Pilot symbol insertion
Department 41i information channel number information generation unit 41j Information generation unit 42,242,342,442 Signal synthesizer 43,830e Frequency time conversion unit 44 Guard interval insertion section 45 antenna 51₁, 51n antenna 52₁, 52n, 152₁, 152n, 352₁, 35
2n, 552₁, 552n, 652₁, 652n, 75
Two₁, 752n, 852₁, 852n, 952 ₁, 95
2n signal processor 52a Symbol timing synchronization unit 52b Guard interval removal unit 52c, 654 time-frequency converter 52d, 655 Spread code generation unit 52e, 656 Spread code multiplication unit 52f, 553, 652c Antenna weight multiplication unit 52g, 52i adder 52h delay device 53,554,653 Antenna signal synthesizer 54, 52j, 552f, 657 Subcarrier weight multiplication
Arithmetic department 55,552g, 658 Symbol synthesizing unit 56 Serial-parallel converter 57 Data demodulator 58 Error Correction Decoding Unit 59 Information symbol restoration unit 81, 181, 481, 581, 681, 811-81
3,881,981 Antenna weight controller 82,182,482,582,682,821-83
0,882,982 sub-carrier weight controller 151 Reception quality measurement unit 241i switching unit 352f collective weight multiplication unit 353 Antenna signal symbol combining unit 441h Insertion of pilot symbol for channel fluctuation estimation
Department 441i Weight update pilot signal insertion unit 441j Information channel signal combining unit 483 collective weight control unit 541h Pilot signal insertion unit for estimating channel fluctuation amount 541i Weight Update Pilot Symbol Insertion Unit 751 Received signal condition measurement unit 752 Judgment section 753 Configuration switching unit 754 Despreading unit after diversity combining 755 Diversity combiner after despreading 811a Signal power comparison unit 811b Selector 812a Weight holding unit 813a Signal power detector 821a, 822a Propagation path fluctuation value detection unit 821b Reciprocal calculation unit 823a Weight holding unit 824a, 825a, 827a, 828a, 829e,
830f Error estimation unit 825b, 828b, 830a Bit string holding unit 824b, 827b, 829f Reference symbol holding unit 825c, 828c, 830b Reference symbol generator 824c, 825d Weight calculation unit 826a, 829a Channel estimation unit 826b, 829b Noise power estimation unit 826c, 829c Code multiplex number estimation unit 826d, 829d Weight calculation unit 827c, 828d, 829g, 830g Weight update unit 829h switching unit 851 Propagation path condition estimation unit 852 Signal power to interference power ratio estimation unit

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Sadayuki Abeta             2-11-1, Nagatacho, Chiyoda-ku, Tokyo Stock             Ceremony company NTT Docomo (72) Inventor Mamoru Sawahashi             2-11-1, Nagatacho, Chiyoda-ku, Tokyo Stock             Ceremony company NTT Docomo F term (reference) 5K022 DD01 DD13 DD19 DD22 DD32                       EE01 EE22 EE32                 5K059 AA08 CC03 DD32 DD35 EE02

Claims (40)

[Claims] 1. A signal obtained by multiplying a plurality of information symbols transmitted on a plurality of information channels by a spreading code for each information channel, the signal being transmitted by a plurality of subcarriers having different frequencies. A plurality of antennas for receiving a plurality of antennas, a spread code multiplication unit for multiplying a received signal received by the plurality of antennas by a spread code of the information channel corresponding to the received signal, and an antenna for multiplying a received signal for each antenna A weight controller for adjusting a weight and a subcarrier weight for multiplying the received signal for each subcarrier; and a weight multiplier for multiplying the received signal by the antenna weight and the subcarrier weight adjusted by the weight controller. A received signal obtained by multiplying the antenna weight and the subcarrier weight by the weight multiplying unit is used as a spread code between the antennas and the spread code. Receiving apparatus characterized by comprising a synthesizing unit for synthesizing over a period. 2. The receiving apparatus according to claim 1, wherein the weight control unit adjusts the antenna weight and the subcarrier weight so that spreading codes of the plurality of information channels are orthogonal to each other. . 3. The weight controller adjusts the antenna weight and the subcarrier weight so that spreading codes of the plurality of information channels are orthogonal to each other and a signal power to noise power ratio is large. The receiving apparatus according to claim 1, wherein 4. The weight control unit adjusts the antenna weight and the subcarrier weight to individually determine the antenna weight and the subcarrier weight, and the weight multiplication unit receives the reception for each antenna. An antenna weight multiplication unit that multiplies a signal by the antenna weight, and a subcarrier weight multiplication unit that multiplies a received signal for each subcarrier by the subcarrier weight, the combining unit includes the antenna weight between the antennas. An antenna signal combining unit for combining the received signals multiplied by and a symbol combining unit for combining the received signals multiplied by the subcarrier weights over the spreading code period. The receiving device according to any one of 3 above. 5. The weight control unit adjusts the antenna weight and the subcarrier weight to determine a collective weight for collectively multiplying the received signals, and the weight multiplying unit determines a subcarrier of each antenna. Each received signal is multiplied by the collective weight, the combining unit, the received signal multiplied by the collective weight,
4. The combination of the antennas and the spreading code period are collectively performed.
The receiver according to item. 6. The received signal for each subcarrier multiplied by the spread code is multiplied by the subcarrier weight, combined over the spread code period, and the received signal for each antenna is multiplied by the antenna weight. The weight multiplication unit and the synthesizing unit perform despreading based on the control of the deciding unit to perform space diversity combining. The receiving device according to claim 1. 7. A measuring unit for measuring a state of a received signal received by the plurality of antennas, wherein the judging unit controls the order based on a state of the received signal measured by the measuring unit. The receiving device according to claim 6, which is characterized in that. 8. The sub-carrier weight multiplication unit is configured such that the antenna weight multiplication unit multiplies a received signal for each antenna by the antenna weight, and the antenna signal synthesis unit multiplies the antenna weight by the antenna. After performing space diversity combining to combine the signals, the received signal for each subcarrier multiplied by the spreading code is multiplied by the subcarrier weight, the symbol combining unit, after the space diversity combining is performed, The receiving apparatus according to claim 4, wherein the receiving signal multiplied by the subcarrier weight is subjected to despreading for combining the received signals over the spreading code period. 9. The antenna weight multiplication unit multiplies the reception signal of each antenna by the antenna weight before separating the reception signal into the reception signal of each subcarrier, and the antenna signal combining unit includes: The receiving apparatus according to claim 8, wherein the reception signals multiplied by the antenna weights are combined between the antennas before the reception signals are separated into the reception signals for each subcarrier. 10. In the antenna weight multiplication unit, the spreading code multiplication unit multiplies the received signal by a spreading code of the information channel corresponding to the reception signal, and the subcarrier weight multiplication unit determines each subcarrier. After multiplying the received signal by the subcarrier weight and performing despreading in which the symbol combining unit combines the received signals multiplied by the subcarrier weight over the spreading code period, the received signal for each antenna is The antenna signal combining unit multiplies the antenna signal by weight, and the antenna signal combining unit performs space diversity combining for combining the received signals multiplied by the antenna weight between the antennas after the despreading is performed. The receiving device according to claim 4. 11. The receiving apparatus according to claim 10, wherein the weight controller determines the antenna weight based on a received signal combined by the symbol combiner over a spreading code period. . 12. A propagation path condition estimation unit that estimates a condition of a propagation path on which the transmitted signal propagates, wherein the weight control unit uses the estimated value of the propagation path condition estimated by the propagation path condition estimation unit. The receiving apparatus according to claim 1, wherein the antenna weight and the subcarrier weight are adjusted based on the antenna weight. 13. An interference situation estimation unit for estimating an interference situation in the received signal, wherein the weight control unit, based on an estimated value of the interference situation estimated by the interference situation estimation unit, determines the antenna weight and the antenna weight. The receiving device according to claim 1, wherein a subcarrier weight is adjusted. 14. A reception quality measuring unit that measures reception quality of information symbols restored from the received signal, wherein the weight control unit is configured to perform the reception quality measurement based on a measurement value of the reception quality measured by the reception quality measuring unit. 14. The receiving apparatus according to claim 1, wherein an antenna weight and the subcarrier weight are adjusted. 15. The receiving apparatus according to claim 1, further comprising: an addition unit that adds the received signals for each subcarrier and averages the signals in the frequency direction or the time axis direction. . 16. A division unit that divides an information symbol transmitted on a plurality of information channels into a plurality of information symbols, and the plurality of information symbols divided by the division unit correspond to an information channel that transmits the information symbols. A symbol duplicating unit that duplicates a number equal to the spreading code period of the spreading code, and a spreading code that multiplies the information symbol duplicated by the symbol duplicating unit by a spreading code corresponding to the information channel that transmits the information symbol to obtain an information signal A multiplication unit, a spreading unit that spreads the information signal multiplied by the spreading code by the spreading code to a plurality of subcarriers having different frequencies for transmitting the information signal, and the spreading unit spreads to the plurality of subcarriers. A transmitting apparatus, comprising: a guard interval inserting unit that inserts a guard interval that prevents interference between the information signals that have been spread. 17. The transmitting apparatus according to claim 16, further comprising: a pilot symbol inserting section that inserts pilot symbols whose amplitude and phase are known in the receiving apparatus for receiving the information signal, into the information symbol. 18. The channel fluctuation amount for inserting a channel fluctuation amount estimation pilot symbol used for estimating a channel fluctuation amount of the information signal in the reception device into the information symbol, in the receiving device. An estimation pilot symbol insertion unit, in the receiving device, an information signal received by the receiving device after despreading, a weight update pilot symbol used for estimation of the error between the information signal transmitted by the transmitting device, 18. A weight update pilot symbol inserting section to be inserted into the information symbol.
The transmission device according to 1. 19. A transmission device for transmitting a signal obtained by multiplying a plurality of information symbols transmitted on a plurality of information channels by a spreading code for each of the information channels by a plurality of subcarriers having different frequencies, A communication system comprising: a reception device that receives a signal transmitted by the transmission device, wherein the reception device includes a plurality of antennas that receive the signal, and a reception signal that is received by the plurality of antennas. A spreading code multiplying unit that multiplies the spreading code of the information channel corresponding to, and a weight control unit that adjusts an antenna weight that multiplies the received signal for each antenna and a subcarrier weight that multiplies the received signal for each subcarrier. A weight multiplication unit that multiplies the received signal by the antenna weight and the subcarrier weight adjusted by the weight control unit; Communication system, comprising the said antenna weights and the reception signals multiplied by the sub-carrier weights, combining unit for combining over the spreading code period between the antenna and the spreading code. 20. A signal obtained by multiplying a plurality of information symbols transmitted on a plurality of information channels by a spreading code for each of the information channels, the signal being transmitted on a plurality of subcarriers having different frequencies. , A plurality of antennas of the receiving device, the receiving device, the received signal received by the plurality of antennas, multiplied by the spread code of the information channel corresponding to the received signal, the received signal for each antenna The antenna weight to be multiplied by and the subcarrier weight to be multiplied to the received signal for each subcarrier are adjusted, the adjusted antenna weight and the subcarrier weight are multiplied to the received signal, and the antenna weight and the subcarrier are Communication in which a received signal multiplied by a weight is combined between the antennas and over a spreading code period of the spreading code. Law. 21. When the receiving device adjusts the antenna weight and the subcarrier weight, it adjusts the antenna weight and the subcarrier weight such that spreading codes of the plurality of information channels are orthogonal to each other. The communication method according to claim 20, wherein: 22. When the receiving device adjusts the antenna weight and the subcarrier weight, spreading codes of the plurality of information channels are orthogonal to each other and a signal power to noise power ratio is increased. 21. The communication method according to claim 20, wherein the antenna weight and the subcarrier weight are adjusted. 23. The receiving apparatus adjusts the antenna weight and the subcarrier weight to individually determine the antenna weight and the subcarrier weight, and multiplies the received signal for each antenna by the antenna weight. 21. The reception signal is combined between the antennas, the reception signal for each subcarrier is multiplied by the subcarrier weight, and the reception signal is combined over the spreading code period. 1 to 22
Communication method described in paragraph. 24. The receiving device adjusts the antenna weight and the subcarrier weight to determine a collective weight for collectively multiplying the received signals, and receives the collective weight for each subcarrier of each antenna. 23. The signal according to claim 20, wherein the received signal multiplied by the collective weight is collectively combined between the antennas and over the spread code period. Communication method. 25. The receiving device multiplies the received signal for each subcarrier multiplied by the spreading code by the subcarrier weight, combines the spread signals over the spreading code period, and forms the received signal for each antenna. Multiplying the antenna weights,
24. The communication method according to claim 20, wherein the order of combining between the antennas is controlled, despreading is performed based on the control, and space diversity combining is performed. 26. The reception device according to claim 25, wherein the receiving device measures a state of a received signal received by the plurality of antennas and controls the order based on the measured state of the received signal. The communication method described. 27. The spread code after the receiving device multiplies a received signal for each antenna by the antenna weight and performs spatial diversity combining for combining the received signal multiplied by the antenna weight between the antennas. The despreading is performed by multiplying the received signal for each subcarrier multiplied by by the subcarrier weight, and combining the received signal multiplied by the subcarrier weight over the spreading code period. 23. The communication method according to 23. 28. The reception signal, wherein the reception device multiplies the reception signal for each antenna by the antenna weight before separating the reception signal into the reception signal for each subcarrier, and the reception signal multiplied by the antenna weight. 28. The communication method according to claim 27, wherein the communication is combined between the antennas. 29. The receiving device multiplies the received signal by a spreading code of the information channel corresponding to the received signal, multiplies the received signal for each subcarrier by the subcarrier weight, After performing despreading in which the received signal multiplied by the weight is combined over a spreading code period, the received signal for each antenna is multiplied by the antenna weight, and the received signal multiplied by the antenna weight is used as the antenna. 24. The communication method according to claim 23, wherein space diversity combining is performed between the terminals. 30. The communication method according to claim 29, wherein the receiving device determines the antenna weight based on a received signal combined over the spreading code period. 31. The receiving device maintains a state of a received signal multiplied by the antenna weight based on an antenna weight multiplied by the received signal, or restores a state of the received signal multiplied by the antenna weight again. 29. The communication method according to claim 27, wherein it is determined whether to adjust, and the subcarrier weight is adjusted based on the determination result. 32. The receiving device determines the antenna weight using an equal gain combining method, and determines the subcarrier weight using either a minimum mean square error combining method or an equal gain combining method. 29. The communication method according to claim 27 or 28. 33. The receiving device maintains a state of a received signal multiplied by the subcarrier weight based on a subcarrier weight multiplied by the received signal or a received signal multiplied by the subcarrier weight. 31. The communication method according to claim 29 or 30, wherein it is determined whether or not to adjust the state again, and the antenna weight is adjusted based on the determination result. 34. The receiving apparatus determines the subcarrier weights using a minimum mean square error combining method, and determines the antenna weights using an equal gain combining method. 30. The communication method according to item 30. 35. The receiving apparatus estimates the condition of a propagation path in which the transmitted signal propagates, and adjusts the antenna weight and the subcarrier weight based on the estimated value of the propagation path condition. The communication method according to any one of claims 20 to 34, which is characterized. 36. The receiving device compares a threshold value of the propagation path condition, which is a criterion for adjusting the antenna weight and the subcarrier weight, with an estimated value of the propagation path condition, and based on the comparison result. 36. The antenna weight and the subcarrier weight are adjusted by adjusting the antenna weight.
The communication method described in. 37. The reception apparatus estimates an interference situation in the received signal, and adjusts the antenna weight and the subcarrier weight based on the estimated value of the interference situation. 37. The communication method according to any one of items 36 to 36. 38. The receiving device compares a threshold value of a difference in interference situation between antennas, which is a criterion for adjusting the antenna weight and the subcarrier weight, with a difference in estimated value of the interference situation between antennas. The communication method according to claim 37, wherein the antenna weight and the subcarrier weight are adjusted based on the comparison result. 39. The receiving apparatus measures the reception quality of the information symbol restored from the received signal, and adjusts the antenna weight and the subcarrier weight based on the measurement value of the reception quality. The communication method according to any one of claims 20 to 38, wherein: 40. The receiving apparatus compares a threshold value of the variation amount of the reception quality, which is a criterion for adjusting the antenna weight and the subcarrier weight, with a variation amount of the measurement value of the reception quality, The communication method according to claim 39, wherein the antenna weight and the subcarrier weight are adjusted based on a comparison result.