JP3385200B2 - Signal transmission method and spreading code synchronization method in mobile communication system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a direct sequence CDMA (DS-C) which performs multiple access using direct sequence.
The present invention relates to a signal transmission method and a spread code synchronization method in a mobile communication system to which a DMA (DMA) communication method is applied.

[0002]

2. Description of the Related Art In a DS-CDMA communication system, a plurality of communicators communicate by using the same frequency band by performing a secondary modulation in which a conventional information data modulated signal is spread by a spreading code of a high rate and transmitting the signal. This is a system in which each communication party is identified by a spread code. Therefore, in the receiver, it is necessary to restore the wideband received input signal to the original narrowband signal in the process of despreading before performing the conventional demodulation processing. In the despreading of this receiver, the correlation between the received signal and the spread code replica synchronized with the spread code phase of the received signal is detected. Particularly, synchronizing the spread code replica of the receiver and the spread code phase of the received signal at the start of communication is called initial synchronization.

The DS-CDMA communication system is a system for transmitting information data by expanding the band with a code having a very high rate compared with the information data rate, and recently research and development aiming at application to a cellular system have been carried out. ing. This is DS-
This is because the CDMA system has characteristics such that the cellular system suitable for high-speed information signal transmission facilitates a flexible cell design which is expected to increase the subscriber capacity as compared with the conventional FDMA and TDMA systems.

In this DS-CDMA system, a spreading code called a short code having a repetition period of an information symbol cycle is used as a spreading code, and a spreading code called a long code having an extremely long repetition period as compared with an information symbol cycle. There is a method of spreading with a code.
A Gold code or the like is used as the spreading code.
The d code is composed of two types of M sequences, but Gold codes belonging to the same group can be generated by the number of repetition periods.

Therefore, in the case of a short code, Gol
The d code can generate only spreading factor (PG) numbers, and in the cellular system, in order to reduce interference from other cells,
The same spreading code must be used with several cells separated, which causes a problem of repeated spreading code arrangement.

On the other hand, when a long code is used, a very large number of codes can be generated by making the repetition cycle very long.

Therefore, in the multi-cell configuration, the spreading code of each correspondent can be independently assigned to each cell.
This is because the number of codes is so large that the same code is very unlikely to overlap with other cells at the same timing.

In the cellular system, there are delayed waves as well as radio waves arriving at the shortest distance from the transmission point due to reflection and diffraction due to surrounding buildings, mountains, steel towers and other features, topography. Usually, this delayed wave becomes an interference signal with respect to the desired wave and deteriorates the reception characteristics. In the DS-CDMA system, since an information signal is transmitted as a very high speed signal, for example, 1
When spread in the MHz band, the desired wave and the delayed wave having a delay of 1 μs can be separated by performing correlation detection with a resolution of 1 μs, and the delay can be achieved by independently demodulating and combining (called RAKE combining). There is an advantage that the electric power of waves can be effectively used.

In this case, in the short code system, consecutive information symbols are spread by the spreading code of the same pattern, so that a delayed wave of more than one information symbol cannot be combined. On the other hand, in the long code, consecutive information symbols are spread by spreading codes of different patterns, so that a delayed wave having a delay of one information symbol or more is also R
AKE can be synthesized.

As described above, the long code has various advantages, but has a demerit that it takes time to synchronize the spread code. That is, in the DS-CDMA receiver, it is necessary to synchronize the spread code phase of the received signal with the phase of the spread code replica in the receiver at the start of communication. Since the long code has much more spreading code phases to search than the short code, it takes a very long time to synchronize.

On the other hand, there are the matched filter shown in FIG. 3 and the sliding correlator shown in FIG. 4 as the structure for detecting the correlation in the receiver.

(Explanation of FIG. 3) The matched filter is constituted by an ExOR circuit because the number of delay elements 1 (normally one chip delay) and the spread code multiplier 2 (spread code replica is binary in the normal case). Can be). The spread modulation signal frequency-converted to the baseband (zero IF frequency) is input to the matched filter for the spread rate, multiplied by the spread code replica from the spread code replica generation unit 3,
The multiplied signals are added by the adder 4. When the phase of the spread modulation signal and the phase of the spread code replica are synchronized, a correlation peak is obtained at the output of the adder 4, and the power of this correlation peak is the spreading factor times the average power in the asynchronous phase. Since the matched filter detects the correlation by the spatial integration as described above, it has an advantage that the initial synchronization time of the spread code is short.

(Explanation of FIG. 4) The sliding correlator multiplies the spread code replica generated from the spread code replica generator 5 and the spread modulation signal by the multiplier 6 (in the normal case, the spread code replica is a binary value, and is therefore an ExOR circuit). Can be configured), and the integration / dump circuit 7 integrates by the diffusion rate. This integration time is usually one symbol period of information. The amplitude-squared detector 8 performs amplitude-squared detection on the integrated signal to generate an amplitude component, and the threshold value judgment circuit 9 judges the threshold value to judge whether or not the phase is a synchronous phase. To do. If the integrated value does not exceed the threshold value, it is determined that the phase is asynchronous, the threshold value determination circuit 9 controls the digital control clock generator 10, and the digital control clock generator 10 causes the spread code replica to be generated. The spreading code replica phase of the output of the generator 5 is J chips (usually J = 1)
Proceed and update. Since the sliding correlator is time-integrated in this way, the circuit scale is smaller than that of the matched filter, but the initial synchronization time is required.

As described above, since the matched filter has a short initial synchronization time because of spatial integration, it has a large circuit scale. On the other hand, the sliding correlator has a small circuit size but has a long initial synchronization time.

A: Type of long code to be searched Q: Total number of chip phases of long code to be searched PG: Spreading factor M: Number of integrated symbols for correlation detection T _C : Chip period N _SC : Number of sliding correlators N _MF : Assuming the number of matched filters, when there is no thermal noise, cross-correlation from other users and delayed waves of the own channel signal, the respective initial synchronization times are as follows.

For a sliding correlator

[0017]

[Formula 1] T _SC = A × Q × PG × M × T _C / N _{SC In} case of matched filter

[0018]

[Formula 2] T _MF = A × Q × M × T _C / N _MF , and in the case of a long code, the code type A and the number of phases Q to be searched are so large that the initial synchronization takes a very long time. There is.

[0019]

As described above, in the mobile communication system using the long code, it is necessary to synchronize the spreading code after the mobile station is turned on and before the control channel from the base station is acquired. There was a problem that it took a very long time.

Further, in a cellular environment where time synchronization between base stations is not established, when a receiver first tries to supplement a channel, an operation of detecting a spread code spreading the received channel (code search) ) Is also required.
Actually, to receive the channels transmitted from multiple base stations, detect the spreading code spreading each channel,
After performing the initial synchronization, the reception level is measured and the channel to be connected is determined. Therefore, in the cellular environment, the time required to complete the initial synchronization of the channel is the time required for the code search, and as described above, when spreading is performed with the long-period spreading code, it may take a very long time.

In a mobile communication environment, the cell (base station) to communicate with changes as the receiver (mobile device) moves. In order to perform this switching, it is necessary for the receiver to periodically measure the reception level (cell search) of the base stations in the vicinity of the base station in communication by synchronizing the spread code of the channel.

Therefore, in a mobile communication system using a long code, an invention is provided which provides a signal transmission method, a transceiver and a spread code synchronization method capable of achieving high speed and high accuracy in initial synchronization of a spread code in a mobile station. Was filed by the inventors of the present application (Japanese Patent Application No. 8-272
696).

FIG. 1 is a diagram showing a basic operation algorithm of the above-mentioned prior invention. In the invention of this prior application, the control channel is spread by using a short code and a long code as the spreading code. The short code is common to a plurality of cells. Further, the long code is a code different for each base station. The long code masks over M symbols at a constant cycle. That is, only the short code is diffused in this masked portion (see FIG. 2). The control channel spread by such a spreading code is transmitted for each base station.

FIG. 5 shows a search method of the initial synchronization method of the long code of the prior invention. In the mobile station, first, the short code common to each cell is used as the spread code replica to detect the correlation with the matched filter.

This correlation detection is performed by this matched filter over the X cycle of the long code, the maximum correlation output peak at this time is detected, and the signal of this correlation peak is connected to the base station.

In this case, since the next long code phase of the symbol in which the long code is masked (spread symbol of only the short code) is predetermined, the long code phase can be known from the maximum correlation output peak phase of the short code. However, since the type of long code differs for each base station, all long codes are searched. This search can be performed with a sliding correlator to reduce power consumption.

At this time, the accuracy of the correlation detection signal can be improved by integrating the signal obtained by integrating the spreading factor among a plurality of information symbols in consideration of the polarity of the signal. In the search in the conventional long code system, it is necessary to search all chip phases of all kinds of long codes, but the method of the present invention can significantly reduce the initial synchronization time. Further, since the matched filter is used only for detecting the correlation of the short code of the first cycle of the long code and the long code is searched by the sliding correlator which consumes less power, the power consumption of the correlation detection circuit can be reduced.

Further, in the search process during communication after the spread codes have been synchronized, the short code of the long code is shorted by using the spread code replica of the short code by the matched filter in the initial synchronization process at power-on. The code correlation peak is detected and the top N of the peaks are stored. In a normal cellular configuration, N is 7 for the base station to be connected and 6 peripheral base stations.

As described above, since the base station having the shortest correlation detection peak (received signal level) of the short code is currently connected, the peripheral cells are controlled to determine the base station of the handover destination accompanying the movement of the mobile station. It is necessary to detect the received signal level of the channel (perch channel). Since the position of the correlation detection value of the short code of the peripheral cells is known in advance, it is only necessary to search what kind of long code each synchronization position is in the order of increasing received signal level. Assuming B, the search time when using a sliding correlator is

[0030]

[Equation 3] T _SC = (B + (B-1) + (B-2) +2) ×
PG × M × T _C / N _SC , and the search time can be greatly shortened. Note that this search time is the search time when there is no false detection rate with no thermal noise or interference signals. In an actual cellular environment, sufficient synchronization is achieved by the thermal noise and the cross-correlation of other communicating parties and delayed waves of the own channel. To obtain the detection probability, it is necessary to lengthen the search time. However, it is obvious that the initial synchronization time can be significantly shortened as compared with the conventional long code serial search.

The present invention provides a signal transmission method, a transmitter / receiver, and a spread code synchronization method capable of further increasing the speed and accuracy of initial synchronization of spread codes in a mobile station in a mobile communication system using a long code. The purpose is to provide.

[0032]

In order to achieve the above-mentioned object, the invention of claim 1 is a direct sequence CDMA communication system for transmitting a signal by expanding a band to a wide band signal by a spreading code having a speed higher than an information rate. , A short-cycle spreading code group common to each base station having a repetition period of the information symbol cycle and a long-cycle spreading code group different for each base station having a longer repetition period than the information symbol cycle are used. A signal obtained by doubly spreading with the first short-cycle spreading code of the cycle-spreading code group and the long-cycle spreading code of the long-cycle spreading code group, and masking the long-cycle spreading code at a constant cycle, is obtained by the reception. The received spread spectrum modulated signal is multiplied by a long cycle spread code of the long cycle spread code group and a first short cycle spread code, and a correlation detection value between the code and the received spread spectrum modulated signal is obtained as a plurality of short cycle spread code frequencies. Detecting over, averaging the detected correlation detection values, the correlation detection value averaged in detecting long-period spreading code for spreading the received signal, the first
The propagation path is estimated using the despread signal at the time position at which the maximum correlation output signal of the short-cycle spreading code and the received spread-modulation signal is obtained as a reference signal, and the short-path spreading code period is used by using the propagation path estimated value. Of the long-cycle spreading code and the first short-cycle spreading code, the data modulation component contained in the correlation output of the code and the received spread-spectrum modulated signal is detected, 1 is characterized in that the data modulation component included in the correlation output of the code multiplied by the short-period spreading code and the received spread modulation signal and the correlation output value from which the phase rotation due to the propagation path fluctuation is removed are averaged by in-phase addition. .

According to a second aspect of the present invention, in addition to the first aspect, the second short-cycle spreading code corresponding to the type of the long-cycle spreading code used in each base station is used to spread the signal burst-wise at a known timing. The propagation channel estimation is performed by receiving the despread signal at the time position where the maximum correlation output signal of the first short cycle spreading code and the received spread modulated signal and the signal spread by the second short cycle spreading code are obtained. At least one of the signals obtained by despreading is used as a reference signal.

According to a third aspect of the present invention, in a direct spread CDMA communication system for transmitting a signal by expanding a band to a wide band signal by a spreading code having a speed higher than an information rate, each base station having a repetition period of an information symbol period. Common short-cycle spreading code group and a long-cycle spreading code group that is different for each base station having a longer repeating cycle compared to the information symbol cycle, and masks the long-cycle spreading code to generate the first short cycle. In transmitting a signal in which the number of times of transmitting a signal spread by only a spreading code is n times with respect to the long-period spreading code period L, and the period is a period L / n at equal intervals, It is characterized in that the signal spread by the third short cycle spreading code indicating the timing of transmitting the head part of the long cycle spreading code is transmitted at a known timing in a burst manner.

According to a fourth aspect of the present invention, in the third aspect, the third short-cycle spreading code indicating the timing of transmitting the head of the long-cycle spreading code is the head of the long-cycle spreading code depending on the pattern of the code to be transmitted. Is represented.

According to a fifth aspect of the present invention, in the third aspect, the third short-cycle spreading code indicating the timing for transmitting the head portion of the long-cycle spreading code has the beginning portion of the long-cycle spreading code according to the timing of transmission. It is characterized in that it represents the timing of transmission.

A sixth aspect of the present invention receives the transmission signal according to any of the third to fifth aspects, observes the correlation between the received signal and the first short period spreading code at the period L / n, and obtains the maximum correlation value. From the timing at which the signal spread only with the first short cycle spreading code is detected, and from the timing at which the signal spread with only the first short cycle spreading code is received, the long The reception timing of the third short-cycle spreading code indicating the timing of transmitting the head part of the cycle-spreading code is detected, and the correlation detection processing of the received signal and the third short-cycle spreading code at the reception timing of the third short-cycle spreading code. Detecting the reception timing of the long cycle spread code from the correlation output value by performing, in the reception timing of the long cycle spread code,
Correlation detection processing is performed between the received signal, each long-cycle spreading code of the long-cycle spreading code group, and the code multiplied by the first short-cycle spreading code, and a long-cycle spreading code for spreading the received signal is detected from the correlation output value. Is characterized by.

According to a seventh aspect of the present invention, in addition to the third to fifth aspects, the signal spread by the second short-cycle spreading code according to the type of the long-cycle spreading code has a known timing in a burst manner. It is characterized by transmitting in.

According to the invention of claim 8, from the timing of receiving the transmission signal of claim 7 and observing the correlation between the received signal and the first short cycle spreading code at the cycle L / n to obtain the maximum correlation value, The timing of receiving the signal spread only by the first short cycle spreading code is detected, and the beginning of the long cycle spreading code is detected from the timing of receiving the signal spread by only the first short cycle spreading code obtained. Detecting the reception timing of the third short-cycle spreading code, which indicates the timing of transmitting the section,
Correlation detection processing between the received signal and the third short cycle spreading code is performed at the reception timing of the third short cycle spreading code, the reception timing of the long cycle spreading code is detected from the correlation output value, and the obtained first short cycle is obtained. The reception timing of the signal spread by the second short cycle spreading code is detected from the timing of receiving the signal spread by only the spreading code or the reception timing of the long cycle spreading code, and spreading is performed by the second short cycle spreading code. The correlation detection processing between the second short-cycle spreading code and the received signal is performed at the reception timing of the generated signal, and the long-cycle spreading code group including the long-cycle spreading code that spreads the received signal is detected from the correlation output value. At the reception timing of the spreading code, each long-cycle spreading code and the first short-cycle spreading code of the long-cycle spreading code group including the received signal and the long-cycle spreading code for spreading the detected received signal. And detecting a long period spreading code for spreading the received signal from the correlation output value performs correlation detection processing between the code multiplied by.

According to a ninth aspect of the present invention, in the first or second aspect, the transmission signal according to any of the third, fourth, fifth and seventh aspects is received, and the first short cycle spreading code and the reception spread modulation signal are combined. Despread the despread signal at the time position where the maximum correlation output signal is obtained, the signal obtained by despreading the signal spread by the second short cycle spreading code, and the signal spread by the third short cycle spreading code. The propagation path is estimated using at least one of the signals obtained as a reference signal, and the propagation path estimation value is used to multiply the long cycle spreading code between the respective short cycle spreading code cycles by the first short cycle spreading code. A data modulation component included in the correlation output between the code and the reception spread modulation signal is detected, and a code obtained by multiplying the long period spread code between the respective short period spread code periods by the first short period spread code and the received spread modulated signal. Data modulation included in the correlation output of Minute and the correlation output value obtained by removing the phase rotation due to the propagation path fluctuation is averaged by in-phase addition, and detecting a long period spreading code for spreading the received signal from the averaged correlation output value.

According to a tenth aspect of the present invention, in a direct spread CDMA communication system for transmitting a signal by expanding a band into a wide band signal by a spreading code having a speed higher than an information rate, each base station having a repetition period of an information symbol period. Common short-cycle spreading code group and a long-cycle spreading code group that is different for each base station having a longer repetition period than the information symbol cycle, the first short-cycle spreading code of the short-cycle spreading code group and A signal that is doubly spread with the long-cycle spreading code of the long-cycle spreading code group and masks the long-cycle spreading code at a constant cycle, and a second signal according to the type of the long-cycle spreading code used in each base station. A signal spread in a burst at a known timing by a short cycle spreading code is received, and a signal spread only by the first short cycle spreading code is received with respect to a received spread signal obtained by the reception. Detection timing of the signal spread by the second short cycle spreading code from the reception timing or the reception timing of the long cycle spreading code, and a plurality of correlation detection processes of the second short cycle spreading code and the received signal are performed at this timing. When a second cycle spreading code is detected by averaging the correlation detection values of the second short-cycle spreading code and the received signal, and a long-cycle spreading code group including the long-cycle spreading code for spreading the received signal is detected from the averaged correlation detection values. In addition, the propagation path is estimated using the despread signal at the time position where the maximum correlation output signal of the first short-cycle spreading code and the received spread modulation signal is obtained as a reference signal,
By using the propagation path estimation value, the phase rotation amount accompanying the propagation path fluctuation included in the correlation detection output between the second short-cycle spreading code and the received signal is detected, and the second short-cycle spreading code and the received signal are detected. It is characterized in that the correlation output values from which the phase rotation due to the propagation path fluctuation included in the correlation detection output is removed are averaged by in-phase addition.

According to an eleventh aspect of the present invention, in the tenth aspect of the present invention, when the transmission signal of the seventh aspect is received, the propagation path estimation is the maximum correlation output between the first short cycle spreading code and the reception spread modulation signal. At least one of the despread signal at the time position where the signal is obtained and the signal obtained by despreading the signal spread by the third short cycle spreading code is used as the reference signal.

According to a twelfth aspect of the invention, from the timing of receiving the transmission signal of any one of the third, fourth and fifth aspects and receiving the signal spread only by the first short cycle spreading code,
The reception timing of the signal spread by the third short-cycle spreading code is detected, and the correlation detection process between the third short-cycle spreading code and the received signal is performed a plurality of times at this timing to perform the third short-cycle spreading code and the received signal. When the reception timing of the long cycle spreading code is detected from the averaged correlation detection values, the maximum correlation output signal between the first short cycle spreading code and the reception spreading modulated signal is obtained. Propagation path estimation is performed using the despread signal at the time position as a reference signal, and the amount of phase rotation associated with the propagation path fluctuation included in the correlation detection output between the third short-cycle spreading code and the received signal using the propagation path estimated value. Is detected, and the correlation output value from which the phase rotation due to the propagation path fluctuation included in the correlation detection output between the third short-cycle spreading code and the received signal is removed is averaged by in-phase addition.

According to a thirteenth aspect of the invention, in the twelfth aspect, the transmission signal of the seventh aspect is received, and the propagation path estimation is
At least a despread signal obtained by despreading the despread signal at the time position where the maximum correlation output signal of the first short-cycle spreading code and the received spread-modulation signal is obtained and the signal spread by the second short-cycle spreading code. One of them is a reference signal.

According to a fourteenth aspect of the present invention, in a direct spread CDMA communication system for transmitting a signal by expanding a band into a wide band signal by a spreading code having a speed higher than an information rate, each base station having a repetition period of an information symbol period. Common short-cycle spreading code group and a long-cycle spreading code group that is different for each base station having a longer repetition period than the information symbol cycle, the first short-cycle spreading code of the short-cycle spreading code group and A signal that is doubly spread with a long-cycle spreading code of the long-cycle spreading code group and that is spread with only the first short-cycle spreading code at a fixed cycle is received, and the received spreading-modulated signal obtained by the reception is received. Then, a correlation detection value between a code obtained by multiplying the long-cycle spreading code of the long-cycle spreading code group by the first short-cycle spreading code and the received spread-modulation signal is detected and detected over a plurality of short-cycle spreading code cycles. Function detection values are averaged, and when detecting a long-cycle spreading code that spreads the received signal from the averaged correlation detection values, the correlation detection between the received signal and the first short-cycle spreading code is performed, and the correlation detection is performed. The first timing for receiving the signal spread only by the first short cycle spreading code is detected based on the magnitude of the correlation value obtained by, and the received signal and the first signal are received at the detected first timing. The correlation detection with the short-cycle spreading code is mutually Δ phase (Δ phase is aTc
Equivalent to: a is a real number, Tc is a chip period), and the first timing is updated based on the magnitude of the correlation value at each timing.

According to a fifteenth aspect of the present invention, in addition to the fourteenth aspect, the signal spread in a burst at a known timing by the second short period spreading code according to the type of the long period spreading code used in each base station is provided. When receiving and detecting the first timing, the correlation between the received signal, the first short-cycle spreading code, and the second short-cycle spreading code is detected.

According to a sixteenth aspect of the present invention, the signal according to the fourteenth aspect further receives a signal spread in a burst at a known timing with a third short-cycle spreading code indicating a timing of transmitting the head portion of the long-cycle spreading code. However, when detecting the first timing, the correlation between the received signal, the first short-cycle spreading code, and the third short-cycle spreading code is detected.

According to a seventeenth aspect of the present invention, in the fifteenth aspect, a signal spread in a burst at a known timing by a third short-cycle spreading code indicating the timing of transmitting the head part of the long-cycle spreading code is received. Then, when detecting the first timing, the correlation between the received signal, the first short-cycle spreading code, the second short-cycle spreading code, and the third short-cycle spreading code is detected. .

The invention of claim 18 is characterized in that the spreading code synchronization method of claim 14 is applied to the spreading code synchronization method of claim 1.

The invention of claim 19 is characterized in that the spreading code synchronization method of claim 15 is applied to the spreading code synchronization method of claim 2.

The invention of claim 20 is characterized in that at least one spreading code synchronization method of claims 14 and 16 is applied to the spreading code synchronization method of claim 6.

The invention of claim 21 is characterized in that at least one spreading code synchronization method of claims 14, 16 and 17 is applied to the spreading code synchronization method of claim 8.

The invention of claim 22 is characterized in that at least one spreading code synchronization method of claims 14, 16 and 17 is applied to the spreading code synchronization method of claim 9.

The invention of claim 23 is characterized in that at least one spreading code synchronization method of claims 14 and 15 is applied to the spreading code synchronization method of claim 10.

The invention of claim 24 is based on the spread code synchronization method of claim 11, and is at least one of claims 14, 16 and 17.
It is characterized by applying two spreading code synchronization methods.

The invention of claim 25 is characterized in that at least one spreading code synchronization method of claims 14 and 16 is applied to the spreading code synchronization method of claim 12.

The invention of claim 26 is based on the spread code synchronization method of claim 13 and at least one of claims 14, 16 and 17
It is characterized by applying two spreading code synchronization methods.

According to a twenty-seventh aspect of the present invention, in a direct sequence CDMA communication system for transmitting a signal by expanding a band into a wide band signal with a spreading code having a speed higher than an information rate, each base station having a repetition period of an information symbol period. Common short-cycle spreading code group and a long-cycle spreading code group that is different for each base station having a longer repetition period than the information symbol cycle, the first short-cycle spreading code of the short-cycle spreading code group and Differently from the first short-cycle spreading code, the long-cycle spreading code is masked at a constant cycle when the signal is transmitted by being double-spread with the long-cycle spreading code of the long-cycle spreading code group. It is characterized in that a signal spread by only a short period spreading code having an autocorrelation characteristic superior to that of one short period spreading code is transmitted.

The invention of claim 28 is characterized in that, in any one of claims 14 to 26, the signal transmitted by the signal transmitting method of claim 27 is received.

[0060]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. In the following description, "common short code" means "first short cycle spreading code" in the claims.
"Long code" means "long period spreading code" in the claims.
The "group identification code" is the "second short-cycle spreading code" in the claims, and the "long code timing confirmation code".
Indicates the “third short period spreading code” in the claims.

FIG. 6 shows an operation example of claim 1 of the present invention. In this transmission frame configuration, the control channel is spread using the short code and the long code as the spreading code. The short code is common to a plurality of cells.
Further, the long code is a code different for each base station. The long code masks over M symbols at a constant cycle. That is, only the short code is diffused in this masked portion. The control channel spread by such a spreading code is transmitted for each base station. Data modulation is performed on the signals spread by the long code and the common short code. In FIG. 6, the case where the two-phase phase modulation method (BPSK modulation) is used as the data modulation is shown as an example. A case will be described in which the correlation between the received signal and the code obtained by multiplying the long code and the common short code is detected in the section of symbols # 0 to # 3 (correlation detection period 1) in the received signal to determine the synchronization of the spread code. To do.

Symbols # 0 to # 3 in the correlation detection period 1
Let s (0) to s (3) be the correlation detection output vectors of the received signal and the code that multiplies the long code and the common short code with the section as the correlation integration time. The phase of s () is rotated according to the symbol data (+1 or -1 in the example). Therefore, if s () is vector summed as it is, correlations may cancel each other out between symbols, and highly accurate correlation detection cannot be performed. In addition, in a mobile communication environment, since amplitude fluctuations and phase fluctuations due to Rayleigh fading due to the movement of the relative position between the mobile station and the base station occur, s () is added to the phase rotation due to data modulation. Amplitude and phase fluctuations due to Rayleigh fading are added and detected.

Therefore, the modulation with the mask symbol is made known in advance, and the correlation detection process between the received signal and the common short code is performed, so that the mask symbol whose reception timing is known is received (in the Rayleigh fading environment) in the absolute phase. It is used to detect. The mask symbol B that is closest in time to the correlation detection period 1
The correlation between the received signal and the common short code is detected at the reception timing of. The correlation detection output (despread signal) vector is p (B). p (B) serves as a reference signal indicating the amplitude fluctuation and phase fluctuation of Rayleigh fading at this time.

Data transmitted is determined based on a signal in which amplitude variation and phase variation of Rayleigh fading obtained from p (B) with respect to s () are compensated (synchronous detection).
In FIG. 6, in order to generate a signal in which the amplitude fluctuation and phase fluctuation of Rayleigh fading are compensated for, P is added to s () as an example.
The complex conjugate of (B) is multiplied. In the example of FIG. 6, since the data modulation is BPSK, the in-phase (I) of the compensated signal is
+1 or -1 is determined from the sign of the component and output as determination data. After data judgment, s () is compensated for data modulation (that is, multiplied by +1 or -1), and then
The vector sum between a plurality of symbols is obtained (S in the figure). In the example of FIG. 6, since the BPSK data modulation, the judgment data is -1.
In the case of, s () is inverted. In this example, the mask symbol used as the reference signal is the symbol closest to the correlation detection period. However, in order to improve the accuracy of the reference signal, a plurality of mask symbols near the correlation detection period 1 (for example, B,
It is also possible to obtain a reference signal by averaging the despread signal vector in C). The invention of the earlier application (Japanese Patent Application No. 8)
-272696), when performing correlation detection for a plurality of multipaths, Rake is generally used.
The accuracy of data modulation detection can be improved by performing the data modulation detection by adding the path diversity known as synthesis.

As described above, according to claim 1 of the present invention, noise and interference components included in the correlation detection value are compared with the case where the sum of correlation square values for each symbol is obtained in order to cancel the data modulation. Can be reduced.

FIG. 7 shows an operation example of claim 2 of the present invention. In the transmission frame configuration of this example, the symbols (a, b, c, d, e ...) Spread by the group identification code are masked symbols (the symbol A spread by the common short code,
B, C, D, E ...) are code-multiplexed. The operation is
In addition to the correlation detection output (despread signal) vector of the received signal at the mask symbol receiving timing and the common short code, the received signal at the receiving timing of the symbol spread by the group identification code It differs from claim 1 of the present invention only in that a correlation detection output (despread signal) vector with a group identification code is also used as a reference signal.

In FIG. 7, as an example of p_ave obtained by averaging p (), the correlation detection outputs of the received signal and the common short code at the reception timings of the two mask symbols in the vicinity of the correlation detection period 1 and the two groups are shown. The simple average of the correlation detection output between the received signal at the reception timing of the symbols spread by the identification code and the group identification code is used. It is possible to easily analogize by using another averaging method.

FIG. 8 shows an example of a transmission frame structure according to claims 3, 4, and 5 of the present invention. Long codes are masked n times at equal intervals for one long code period. Figure 8
In Example 1, the symbol next to the symbol in which the long code is masked (spread with the common short code) is the symbol spread with the long code timing confirmation code. As the long code timing confirmation code, different spreading codes c # 0 to c # n-1 are used depending on the number of long code masks from the head position of the long code. In Example 2 of FIG. 8, similarly, the long code timing confirmation code is different from the spreading code c # 0 to c # n depending on the number of long code masks from the start position of the long code.
-1 is used, but the symbols spread by the long code timing confirmation code are code-multiplexed with the mask symbols (symbols spread by the common short code). In Examples 1 and 2 of FIG. 8 described above, the pattern of the spreading code used as the long code timing confirmation code indicates the head position of the long code.

In Examples 3 and 4 of FIG. 8, the symbols spread by the long code timing confirmation code are arranged from the head position of the long code to the symbols next to the first mask symbol (the symbol spread by the common short code). Alternatively, the code is multiplexed at the mask symbol position.

In Example 5 of FIG. 8, in addition to Example 3 of FIG. 8, in addition to the first mask symbol from the beginning position of the long code,
The symbols spread by the long code timing confirmation code are also added to the second symbol. In Examples 3, 4, and 5 of FIG. 8 described above, the pattern of the transmission position of the symbols spread by the long code timing confirmation code indicates the beginning position of the long code.

In Example 6 of FIG. 8, a long code timing confirmation code c # is assigned to each of the first mask symbol (the symbol spread by the common short code) and the second mask symbol from the beginning position of the long code to the next symbol. Symbols spread by 0 and c # 1 are arranged. In Example 6 of FIG. 8 described above, the start position of the long code is indicated by using both the pattern of the spreading code used as the long code timing confirmation code and the pattern of the transmission position of the symbol spread by the long code timing confirmation code. There is.

Many transmission methods are conceivable in addition to the frame structure shown in the above example. A symbol spread by a long code timing confirmation code with respect to a mask symbol (symbol spread by a common short code) transmission position. The condition is that the transmission position and the pattern of the spreading code used as the long code timing confirmation code are already known on the receiving side.

FIG. 9 shows an example of a transmission frame structure according to claim 7 of the present invention. Long codes are masked n times at equal intervals for one long code period. Further, in each of the following examples, as the transmission pattern of the long code timing confirmation code, each pattern including the example shown in FIG. 8 can be applied. In Example 1 of FIG. 9, the symbol next to the symbol with the long code masked (spread with the common short code) is spread with the long code timing confirmation code, and the next symbol is spread with the group identification code. It is used as a symbol.

In Example 2 of FIG. 9, the symbols spread by the long code timing confirmation code and the symbols spread by the group identification code are code-multiplexed on the mask symbol (symbol spread by the common short code). In Example 3 of FIG. 9, a symbol in which the symbol spread by the long code timing confirmation code and the symbol spread by the group identification code are code-multiplexed at the next symbol position of the mask symbol (symbol spread by the common short code). It is arranged. In Example 4 of FIG. 9, the symbols spread by the group identification code are code-multiplexed with the mask symbols (symbols spread by the common short code), and the symbol spread by the long code timing confirmation code is the beginning of the long code. It is arranged only at the symbol position next to the first mask symbol from the position.

In Example 5 of FIG. 9, the long code mask is performed for two consecutive symbols, and the symbols masked by the groove identification code are code-multiplexed with the leading mask symbol (the symbol spread by the common short code). Therefore, the symbols spread by the long code timing confirmation code are code-multiplexed with the subsequent mask symbols (symbols spread by the common short code). In Example 6 of FIG. 9, k (k <n−) is read from the start position of the long code.
At 1) long code mask positions, symbols spread by the group identification code are code-multiplexed with mask symbols (symbols spread by the common short code), and then at nk long code mask positions. The symbol spread by the long code timing confirmation code is code-multiplexed with the mask symbol (symbol spread by the common short code).

Many transmission methods are conceivable in addition to the frame structure shown in the above example. A symbol spread by a long code timing confirmation code with respect to a mask symbol (symbol spread by a common short code) transmission position. The transmission position and the spreading code pattern used as the long code timing confirmation code, and the transmission position of the symbol spread by the groove identification code and the spreading code pattern used as the group identification code are known to the receiving side in advance. The condition is that

FIG. 10 shows an operation flow of the spread code synchronization method according to claim 6 of the present invention. The applied transmission frame structure is, for example, as shown in FIG. First, the invention of the prior application (Japanese Patent Application No. 8)
No. 272696), the timing of the long code mask is obtained by detecting the correlation between the received signal and the common short code. Next, the reception timing of the symbol spread by the long code timing confirmation code is obtained from the detected timing of the long code mask. In the case of Example 1 in FIG. 8, the timing is one symbol period (common short code period) delayed from the long code mask timing. The correlation between the received signal and the long code timing confirmation code is detected at the reception timing of the symbols spread by the long code timing confirmation code.
In the case of the example 1 in FIG. 8, the correlation is detected in each code of c # 0 to c # n-1. In the case of Example 3 in FIG. 8, the correlation is detected at c # 0. This correlation detection is performed at the reception timing of the symbols spread by the continuous long code timing confirmation code n times. The obtained correlation value is represented by S (a, x). Here, a is the number of the long code timing fixed code used for correlation detection, 0 ≦ a ≦ n−1, and x is the order of correlation detection (first correlation detection is 0, next is 1, ... , And 0 ≦ x ≦ n−1. Further, each correlation value is a value after square-law detection, and S ≧ 0. further,
The transmission pattern of the long code timing confirmation code, which is known in the mobile station, is represented by P (i, a) in association with the long code mask symbol number i (0≤i≤n-1). P (i, a) takes a value of 1 or 0, and gives 1 to the number of the long code timing confirmation code to be transmitted and 0 to the number of the long code timing confirmation code to not be transmitted. In the case of the example 1 in FIG. 8, when i = a, P
(I, a) = 1, otherwise 0. In the case of Example 3 in FIG. 8, only P (0,0) is 1, and in other cases it is O.

After the correlation is detected, the following correlation sum D (x) is obtained. That is,

[0079]

[Equation 4]

Find Here, when the x-th correlation detection is performed at the reception timing of the symbol spread with the long code timing confirmation code corresponding to the long code mask symbol number 0 of the received signal, the transmission pattern of the long code timing confirmation code is detected. Since the peak appearance pattern of the correlation value is matched, D (x) becomes maximum. Since the reception timing of the long code mask symbol corresponding to the long code mask symbol number can be known from this, the reception timing of the long code can be detected.

The next long code identification is performed by the same method as the invention of the prior application (Japanese Patent Application No. 8-272696), but for each long code, n kinds of 1 / n long code periods are used. It is not necessary to detect the correlation between the long code having a corresponding phase difference and the received signal, and the long code and common short code set to the synchronization phase obtained from the reception timing of the long code detected by the long code timing confirmation code Correlation detection between the code multiplied by and the received signal is detected for each long code candidate, and the long code of the received signal is identified from the magnitude of the correlation value. As described above, according to the present invention, it is not necessary to perform correlation detection for n types of long codes in long code identification, so that the time required for establishing synchronization can be shortened.

FIG. 11 shows an operation flow of the spread code synchronization method according to the eighth aspect of the present invention. Here, in the operation flow of the spread code synchronization method according to claim 6 of the present invention, the prior invention (Japanese Patent Application No. 8-2726)
Detection of the long code group shown in 96) is performed after detection of the long code mask timing. The applied transmission frame structure is as shown in FIG. 9, for example. In the detection of the long code group, the correlation between the received signal and the group identification code candidate is detected at the reception timing of the signal spread by the group identification code obtained from the timing of the detected long code mask. The correlation sum in the transmission pattern of the known group identification code is detected in advance with respect to the obtained correlation detection value, and the long code group to be subjected to the identification determination is determined from the transmission pattern that obtains the maximum correlation sum. In long code identification, instead of detecting the correlation between all the long codes prepared in the system and the received signal, correlation detection may be performed only on the long codes included in the detected long code group. In FIG. 11, the long code group is detected after the detection of the long code reception timing, but these two detections can be performed simultaneously or in a different order.

FIG. 12 shows an operation example of claim 9 of the present invention.
The operation is the correlation detection output (despread signal) vector of the reception signal at the reception timing of the mask symbol and the common short code according to claim 1 or 2 of the present invention,
Received signal at the reception timing of the symbol spread by the group identification code and the correlation detection output (despread signal) vector between the group identification code and the received signal at the reception timing of the symbol spread by the long code timing confirmation code The present invention is different from claim 1 or claim 2 only in that the correlation detection output (despread signal) vector of the long code timing fixed code is also used as the reference signal. In FIG. 12, as an example of p_ave obtained by averaging p (), the correlation detection output between the reception signal and the common short code at the reception timing of the two mask symbols in the vicinity of the correlation detection period 1 and the two groove identification codes are used. Correlation detection output between the received signal at the reception timing of the spread symbols and the group identification code, and the correlation between the received signal at the reception timing of the symbols spread by the two long code timing confirmation codes and the long code timing confirmation code A simple average of detection output is used. It is possible to easily analogize by using another averaging method. The frame configuration is not limited to that shown in FIG. 12, and it can be easily inferred that other frame configurations as shown in FIG. 9 can be used.

FIG. 13 shows the present invention as claimed in claims 10, 11, 12,
13 shows an operation example. In a mobile communication environment, because of amplitude fluctuations and phase fluctuations due to Rayleigh fading due to the movement of the relative position between the mobile station and the base station,
In the correlation detection output vector s (), phase rotation due to data modulation and amplitude and phase fluctuation due to Rayleigh fading are added and detected. Therefore, as an example, the correlation detection output s between the received signal and the group identification code at the reception timing of the symbols Cm and Cn spread by the group identification codes separated from each other so that the fading fluctuation cannot be ignored.
Considering the averaging of (Cm) and s (Cn), if the averaging is performed for each of the in-phase (I) component and the quadrature (Q) component, the phase rotation amount due to Rayleigh fading differs (θ
By using (m) and θ (n), it becomes difficult to obtain an accurate magnitude of the average correlation output. Therefore, in the tenth aspect of the present invention, θ (m) is estimated using the correlation output s (Am) between the symbol spread only by the common short code by the long code mask and the common short code.
In Example 1 of FIG. 13, as the estimated value θ_ave (m), s
The phase rotation amount θ (Am) of (Am) is used as it is. Further, in the example 2 of FIG. 13, the estimated value θ_ave (m)
As the correlation detection value s (Am− for symbols Am−1 and Am + 1 that are temporally close to the symbol Cm.
1), the amount of phase rotation θ (Am + 1) obtained from s (Am + 1)
−1) and θ (Am + 1) are also weighted and averaged. By averaging, θ (m) can be detected with higher accuracy, but the phase variation due to Rayleigh fading increases as the distance from the symbol Cm increases with time, so the amount of phase rotation obtained from the correlation value with a symbol that is too far away is averaged. This results in deterioration of the estimation accuracy of the phase rotation amount. Next, the amount of phase rotation θ_ave estimated from s (Cm)
A correlation vector s' (Cm) obtained by inversely rotating (m) is obtained. Similarly, for S (Cn), s' (Cn) is obtained,
Average of two correlation values S_ave = s ′ (Cm) + s ′ (C
n).

Further, according to claim 11 of the present invention, when the transmission frame of claim 7 of the present invention is used, when the long code reception timing is detected prior to the detection of the long code group, the phase rotation amount θ (m ) The correlation output s (Bm) between the symbol Bm spread by the long code timing confirmation code and the long code timing confirmation code
Also used. In Example 3 of FIG. 13, the estimated value θ_ave (m)
As the phase rotation amount θ (Am) of s (Am) and s (B
The simple average of the phase rotation amount θ (Bm) of m) is used.
Further, in Example 4 of FIG. 13, the estimated value θ_ave (m) is the symbol A at a position temporally close to the symbol Cm.
Correlation detection values s (Am-1), s (Bm-1), s (Am +) at m-1, Bm-1, Am + 1, Bm + 1.
1), phase rotation amount θ (Am obtained from s (Bm + 1)
−1), θ (Bm−1), θ (Am + 1), θ (Bm +
1) is also weighted and averaged.

According to claim 12 of the present invention, claim 3 of the present invention
When using 4, 5 transmission frames, the correlation between the received signal at the reception timing of the symbols Bm and Bn spread by the long code timing confirmation code and the long code timing confirmation code when the long code reception timing is detected When the detection outputs s (Bm) and s (Bn) are averaged, the phase rotation due to fading is corrected using s (Am) as in claim 10 of the present invention, and then synchronous addition is performed. Is the claim 1 of the present invention described above.
In the operation example of 0, Cm is replaced with Bm.

Further, according to claim 13 of the present invention, when the transmission frame of claim 7 of the present invention is used, when the long code group is detected prior to the detection of the long code reception timing, the phase rotation amount θ (m The correlation output s (Cm) of the symbol Cm spread by the group identification code and the long code timing confirmation code is also used for the estimation of)), and the operation example is the operation example of claim 11 of the present invention described above. Cm is replaced with Bm.

As described above, claims 10, 11, 12, 13 of the present invention
In the implementation of, the averaging means for detecting the phase rotation amount θ can use other commonly known averaging methods. Also, when averaging two or more symbols, it can be easily realized by expanding the same procedure. According to claims 10, 11, 12, and 13 of the present invention, since correlation values between a plurality of symbols can be averaged by in-phase addition, correlation 2
It is possible to reduce noise and interference components included in the average correlation detection value, as compared with the case where the average of the power values is calculated.

FIG. 25 shows an example of basic operation according to claims 14 to 17 of the present invention. When the clocks of the transmitter and the receiver are deviated from each other, the sampling timing of the received signal deviates with time, so that the synchronization position appears to deviate from the viewpoint of the receiver. Therefore, when the long code is identified with respect to the synchronization timing detected by the long code synchronization timing detection, the long code is identified at a timing deviated from the true synchronization timing with the passage of time, and the spread code synchronization accuracy is improved. And the speed will deteriorate.

Therefore, in claims 14 to 17 of the present invention, as shown in FIG. 25, after the long code synchronization timing detection by the long code mask timing detection circuit described above is performed, long code mask symbols (common The long code synchronization timing position is tracked using a symbol spread only by the short code). That is, as described above, basically, after detecting the long code synchronization timing, the process moves to the identification of the long code, but the long code mask symbol periodically received in parallel with the identification detection process of the long code. And the correlation between the received signal and the common short code at the timing deviated by ± Δ phase (Δ phase corresponds to aTc: a is a real number, Tc is a chip period). In general, 1/2 or 1/4 is used as a. When there is no frequency drift, the correlation detection value at the reception timing of the long code mask symbol is maximized. However, in an environment where there is an actual frequency drift, the reception timing of the detected long code mask symbol deviates from the reception timing of the actual long code mask symbol, so + (or −) The correlation value detected increases with the Δ phase shift timing. Therefore, the reception timing of the long code mask symbol deviated due to the frequency drift can be detected by comparing and detecting which of the correlation values of 0 and ± Δ phases (that is, three) is the largest.

By performing the long code identification process using the reception timing detection value of the latest long code mask symbol obtained in this way, the long code of the received signal and the receiver side are always used even if there is a frequency drift. It is possible to keep the synchronization with the prepared long code.

The correction (update) of the reception timing of the long code mask symbol using the correlation value of 0, ± Δ phase is
In an actual environment, since each correlation value contains a component of thermal noise or inter-channel interference, it is performed after averaging the correlation values to some extent. Further, as the correction method, a generally known tracking method for spreading code synchronization can be used. As a first example, the average correlation value at 0 and ± Δ phases is obtained, and when the correlation value at 0 phase is maximum, no correction is performed and the correlation value at + (−) Δ phase becomes maximum. If
The detection value of the reception timing of the long code mask symbol is advanced (delayed) by a time corresponding to the Δ phase. In addition, in the second example, the correlation detection in the 0 phase is not performed, the average correlation values of the + (−) Δ phases are compared, and the timing at which a larger correlation value is obtained is detected as the reception timing of the new long code mask symbol. The value. In either case, when the detection value of the reception timing of the new long code mask symbol is obtained, this timing is set to 0 phase and the above operation is repeated. In addition, using three or more correlators (example 5, 0, ± Δ, ±
(2Δ phase) It is also possible to perform tracking of the reception timing of the long code mask symbol.

When the long code group detection and the long code reception timing detection (in the case of the equally spaced long code mask) are performed, the reception timing of the long code mask symbol updated as described above is also used in these processes. The detected value can be used. Further, in this case, the correlation between the received signal and the group identification code or the long code timing confirmation code is detected in the same manner as above (after completion of these processes if necessary), and the obtained 0, ± Δ phase is obtained. To the correlation value of 0, ± Δ phase between the received signal and the common short code (in phase)
The timing at which the maximum correlation value is obtained by addition can be used for long code group detection, long code reception timing detection, and long code identification timing correction.

Claims 14 to 17 of the present invention show examples thereof in FIGS. 36 to 39 described later and application examples thereof in FIGS. 26 to 35, but in addition to FIGS. It can also be applied to each embodiment shown in the invention (Japanese Patent Application No. 8-272696).

[0095]

FIG. 14 shows a code spread processing portion of a downlink channel transmitter in a cellular base station as an embodiment of a code spread method of a mobile communication system to which the present invention is applied.
The configuration shown in FIG. 14 can be applied to each claim of the present invention. In the downlink channel, the long code is common in each base station for ease of handover. Therefore, the long code spreading section can be made common by spreading the signal after bundling the control channel and the communication channel in communication with a common long code.

As shown in FIG. 14, the control channel information signal is repeated from the common short code generation section 11 and each communication channel information signal is repeated from the communication channel short code generation section 12 in the information symbol cycle. It is spread with different short codes having a period.
The control channel information signal is further spread at a predetermined timing with a group identification code from the group code generation unit 13 and with a long code timing fixed code from the long code timing fixed code generating unit 14 as necessary. . After that, only the control channel information signal is spread by the inversion spreading code from the long code inversion code (complex conjugate) generation unit 15 which is a complex conjugate of the common long code. After that, the adder 16 adds the signals of all the channels at an appropriate timing, and then the long code from the long code generation unit 17 is used to add the adder 13
The signals of all channels of the output of are spread and output as spread modulation signals. Reference numeral 18 denotes a timing control unit, which is the operation timing of each generation unit and the switches 22, 23, 2
Control 4 Reference numeral 19 is a multiplier. Reference numerals 20 and 21 are adders. The switch 24 controls whether or not the control channel information signal in which the common short code is spread is supplied to the adder 16. The switch 23 controls whether the group identification code is multiplexed on the control channel information signal in which the common short code is spread, and the switch 22 controls whether the long code timing confirmation code is further multiplexed. The long code inversion code generation unit 15 multiplies an inversion spreading code that is a complex conjugate of a common spreading long code only between information symbols that mask long codes, and multiplies all 1s at other timings (that is, , The state where the inverse spread code is not multiplied). After that, by multiplying the long code from the long code generation unit 17 in common with other communication channels, as a result, the masked portion is in a state in which the diffusion of the long code is canceled.

With this configuration, the long code spreading section in the base station transmitting section can be made common to all control channels and communication channels.

(Claim 1) FIG. 15 is a block diagram corresponding to claim 1, and operates as follows.

1. The long code mask timing detection circuit 25 detects the reception timing of the long code mask symbol. That is, the spread code replica to the matched filter 26 to which the received spread modulation signal is input is the short code code of the long code mask portion common to each base station from the short code replica generator 27. Correlation detection is performed by the matched filter 26 over the reception spread modulation signal over N long code periods, and the correlation value indicating each peak obtained as a result and its timing are stored in the memory 28, and the maximum correlation is stored from the stored value in the memory 28. The maximum correlation value and the timing are selected by the output selection circuit 29 and stored in the memory 30. The memory 30 outputs the long code mask timing detection signal.

2. The phase of the long code replica generator 31 is set to the synchronization phase obtained from the long code mask timing detection signal (long code phase initial setting).

3. The integration / dump circuit 32 integrates the correlation (complex) between the reception spread modulation signal and the long code (1
Information symbol period).

4. The integration / dump circuit 33 integrates the correlation between the reception spread modulation signal at the reception timing of the long code mask symbol and the common short code from the short code replica generator 27.

5.4. The channel estimation value (complex) is detected in the channel estimation circuit 34 from the correlation integration value (complex) of (in the example, the complex correlation integration value of 4. is directly used as the channel estimation value. It is also possible to use.)

6.5. The complex conjugate of the channel estimates of The correlation integral value (complex) obtained by multiplying the correlation integral value (complex) of is multiplied to obtain the channel.

7.6. The hard-decision is made in the data decision circuit 35 for the correlation integral value (complex) that compensates the channel of, and the data modulation component is detected.

8.3. From the correlation integral value (complex) of 7. The correlation integral value from which the data modulation component detected in 3 is removed is detected over a plurality of symbols, and the complex signal averaging circuit 36 averages it in a complex manner.

9. The value obtained by square-law detection of the correlation integrated value (complex) after averaging by the square-law detector 37 is threshold-value judged by the comparator 38. That is, the signal exceeding the threshold value is output to the well-known demodulation / RAKE synthesizing circuit as a signal for which synchronization can be determined. If the threshold value is not exceeded, the long code type of the long code replica generator 31 is changed according to the determination signal from the comparator 38. The threshold value in the comparator 38 is determined by the threshold value determination circuit 39 to be the threshold value corresponding to the maximum correlation value from the long code mask timing detection circuit 25.

(Claim 2) FIG. 16 is a block diagram corresponding to claim 2, and operates as follows.

1. In the long code mask timing detection circuit 25, the reception timing of the long code mask symbol is detected. (In claim 2, since the group code is used as the short code in addition to the common short code, the short code replica generator 27 is commonly used. The short code replica generator 27A is used).

2. The memory 30 of the long code mask timing detection circuit 25 outputs the reception timing of the signal spread by the known group code in the reception signal in response to the reception timing of the long code for which the maximum correlation is obtained. In the long code group detection circuit 40, the memory 3
At the reception timing of this group code from 0, each group code replica generated for the number of group codes by the group code replica generator 41 is multiplied by the reception spread modulation signal, and the multiplied signal is integrated / dumped. Each square symbol 42 is integrated for one symbol, and then squared detector 43
Square detection is performed at. The obtained square-law detection value of the correlation integral value for each group code is stored in the memory 44. The above operation is performed on the signals spread by the plurality of received group codes and stored in the memory 44. When the correlation detection is completed, the sum of the correlation values according to the transmission pattern of each candidate group code is detected with respect to the squared detection value of the correlation integral value for the number of group codes × correlation detection times obtained from the memory Determined by the circuit 45. The sum of correlation values of the number of transmission patterns of the obtained candidate group code is compared by the selection circuit 46, and the pattern having the maximum sum of correlation values is selected and output.
The long code group detection circuit 47 detects a long code group including a long code for spreading the received spread modulation signal from the pattern output from the selection circuit 46.

3. The phase of the long code replica generator 49 in the long code identification circuit 48 is set to 1. It is set to the synchronization phase obtained from the long code mask timing detected in.

4. The integration / dump circuit 50 integrates the correlation (complex) between the reception spread modulation signal and the long code (one information symbol period).

5. The integration / dump circuit 52 integrates the correlation between the reception spread modulation signal at the reception timing of the long code mask symbol and the common short code from the common short code replica generator 51.

6. The integration / dump circuit 54 integrates the correlation between the reception spread modulation signal at the reception timing of the group code spread symbol and the group code from the group code replica generator 53.

7.5. And 6. The channel estimation value (complex) is detected in the channel estimation circuit 55 from the correlation integral value (complex) of.

8.7. The complex conjugate of the channel estimation value of 4 is multiplied by the correlation integral value (complex) of 4 to obtain the channel-compensated correlation integral value (complex).

9. The data decision circuit 56 makes a hard decision on the correlation integral value (complex) that compensates the channel of 8. and detects the data modulation component.

10.4. 9. From the correlation integral value (complex) of
Of the complex signal averaging circuit 5 for detecting the correlation integral value from which the detected data modulation component of
7. Complex and average at 7.

11. The correlation integrated value (complex) after averaging is 2
The threshold value determination circuit 59 performs threshold value determination on the value obtained by square-law detection by the multiplicative detector 58. The threshold value determination circuit 59 determines the threshold value to a threshold value corresponding to the maximum correlation value from the long code mask timing detection circuit 25 by the threshold value determination circuit 60.

(Claim 6) FIG. 17 is a block diagram corresponding to claim 6, and operates as follows.

1. The long code mask timing detection circuit 25 detects the reception timing of the long code mask symbol.

2. In the long code reception timing detection circuit 61, 1. On the basis of the long code mask timing detected in step 1, the received spread modulation signal and the long code timing fixed code replica generators 62 corresponding to the number of received spread modulated signals and long code timing fixed codes are received at the reception timing candidates of the symbols spread by the long code timing fixed code. The correlation with each long code timing confirmation code is detected.

3. The integration / dump circuit 63 integrates the detected signals by one symbol period, and then the square detector 64
Square detection is performed at.

4.3. The long code timing fixed code number, the correlation value, and the correlation detection time obtained as a result of the above are stored in the memory 65.

5.4. With respect to the correlation value obtained in step 1, the detection circuit 66 detects the correlation value sum corresponding to the transmission pattern of the long code timing confirmation code by changing the correlation detection time, and then the selection circuit 67 detects the maximum correlation value sum. To detect the correlation detection time.

From the correlation detection time obtained in 6.5, the long code timing detection circuit 68 detects the long code reception timing.

7. In the long code identification circuit 69,
6. The long code is identified by using the reception timing of the long code detected in. That is, the long code from the long code replica generator 70, which has initialized the long code phase according to the reception timing of the long code, is multiplied by the received spread modulation signal, the integration / dump circuit 71 performs integration, and the square wave detector 72 outputs 2 The long code is identified by performing multiplicative detection and threshold determination by the threshold determination circuit 73. Threshold decision circuit 73 and threshold decision circuit 7
The operation of No. 4 is the same as the operation of the threshold decision circuit 59 and the threshold decision circuit 60 of FIG.

(Claim 8) FIGS. 18 and 19 are block diagrams corresponding to Claim 8 and operate as follows.

1. The long code mask timing detection circuit 25 detects the reception timing of the long code mask symbol.

2. In the long code reception timing detection circuit 61, 1. The long code reception timing is detected based on the long code mask timing detected in.

3. The long code group detection circuit 40 detects the long code group including the long code of the reception spread modulation signal using the reception timing of the long code detected in 2.

4. In the long code identification circuit 69,
2. Reception timing of the long code detected in 3. The long code is identified using the long code group detected in.

(Claim 9) FIG. 20 is a block diagram corresponding to claim 9, which is characterized by a long code identifying circuit 75 and has another structure, that is, a long code mask timing detecting circuit 25 and a long code. The operations of the reception timing detection circuit 61 and the long code group detection circuit 40 are the same as those of the above-mentioned claims. Long code identification circuit 7
5, the correlation integral value between the reception spread modulation signal at the reception timing of the long code mask symbol and the common short code from the common short code replica generator 51, and the reception spread modulation signal at the reception timing of the group code spread symbol. Group code replica generator 53
In addition to the correlation integration value with the group code from, the correlation integration value between the received spread signal at the reception timing of the long code timing defined code spreading symbol and the long code timing defined code from the long code timing defined code replica generator 76. The channel estimation value (complex) is detected in the channel estimation circuit 55A from (by the integration / dump circuit 77). The operation of the configuration after the data determination circuit 56A is the same as that in the long code identification circuit 48 of FIG.

(Claim 10) FIG. 21 is a block diagram corresponding to claim 10, in which a long code group detection circuit 78 is provided.
Another configuration, namely, the long code mask timing detection circuit 25 and the long code identification circuit 48.
The operation of is the same as that of each of the preceding claims. The operation of the long code group detection circuit 78 is as follows.

1. Based on the long code mask timing detected by the long code mask timing detection circuit 25, the group from the group code replica generator 79 of the reception spread modulation signal at the reception timing of the group code spread symbol and the group code number at the reception timing. Correlation (complex) with code is integrated / dump circuit 80
Integrate with.

2. The integration / dump circuit 82 integrates the correlation between the reception spread modulation signal at the reception timing of the long code mask symbol and the common short code from the common short code replica generator 81.

The channel estimation value (complex) is detected by the channel estimation circuit 83 from the correlation integral value (complex) obtained in 3.2.

4.3. The complex conjugate of the channel estimation value of is multiplied by the correlation integral value (complex) of 1. to obtain the channel-compensated correlation integral value (complex).

5.1. ~ 4. are performed at the reception timing of a plurality of group code spread symbols, and the obtained correlation integral value (complex) after channel compensation is calculated by the complex signal averaging circuit 84.
By averaging with complex.

6. A long code group including a long code of the received signal is detected using a value selected by square-law detection of the averaged correlation integral value (complex) by a square-law detector 85. Configuration for that (memory 86, detection circuit 87, selection circuit 8
8. The long code group detection circuit 89) is the same as that in the long code group detection circuit 40 of FIG.

(Claim 11) FIG. 22 is a block diagram corresponding to claim 11, in which a long code group detection circuit 90 is provided.
The other configurations, that is, the operations of the long code mask timing detection circuit 25, the long code reception timing detection circuit 61, and the long code identification circuit 69 are the same as those of the above claims. The operation of the long code group detection circuit 90 is as follows.

1. Based on the long code reception timing detected by the long code reception timing detection circuit 61, the group from the group code replica generator 79 of the reception spread modulation signal at the reception timing of the group code spread symbol and the group code number at the reception timing. An integration / dump circuit 80 integrates the correlation (complex) with the code.

2. The integration / dump circuit 82 integrates the correlation between the reception spread modulation signal at the reception timing of the long code mask symbol and the common short code from the common short code replica generator 81.

3. The integration / dump circuit 92 integrates the correlation between the reception spread modulation signal at the reception timing of the long code timing fixed code spreading symbol and the long code timing fixed code from the long code timing fixed code replica generator 91.

4.2. And 3. The channel estimation value (complex) is detected in the channel estimation circuit 83A from the correlation integral value (complex) obtained in (1).

5.4. The complex conjugate of the channel estimation value of is multiplied by the correlation integral value (complex) of 1. to obtain the channel-compensated correlation integral value (complex).

6.1. ~ 5. are performed at the reception timing of a plurality of group code spread symbols, and the obtained correlation integral value (complex) after channel compensation is calculated by the complex signal averaging circuit 84.
By averaging with complex.

7. A long code group including a long code of the received signal is detected by using a value obtained by square-law detection of the averaged correlation integrated value (complex) by the square-law detector 85. Configuration for that (memory 86, detection circuit 87, selection circuit 8
8. The long code group detection circuit 89) is the same as that in the long code group detection circuit 40 of FIG.

(Claim 12) FIG. 23 is a block diagram corresponding to claim 12, which is characterized by the long code reception timing detection circuit 93 and has another configuration, that is, the long code mask timing detection circuit 25. The operation of the long code identification circuit 69 is the same as that of the above-mentioned claims. The operation of the long code reception timing detection circuit 93 is as follows.

1. Based on the long code mask timing detected by the long code mask timing detection circuit 25, the long code timing of the long code timing fixed code spread symbol and the received spread modulated signal at the reception timing of the long code timing fixed code spread symbol The long code timing from the fixed code replica generator 94 is integrated with the fixed code.
The dump circuit 95 integrates.

2. The integration / dump circuit 97 integrates the correlation between the reception spread modulation signal at the reception timing of the long code mask symbol and the common short code from the common short code replica generator 96.

3.2. The channel estimation value (complex) is detected in the channel estimation circuit 98 from the correlation integral value (complex) obtained in (1).

4.3. The complex conjugate of the channel estimation value of is multiplied by the correlation integral value (complex) of 1. to obtain the channel-compensated correlation integral value (complex).

5.1. ~ 4. Is performed at the reception timing of a plurality of long code timing fixed codes, and the obtained correlation integral value (complex) after channel compensation is averaged by a complex signal averaging circuit 99 in a complex manner.

6. The reception timing of the long code is detected using the value obtained by squaring detection of the averaged correlation integral value (complex) by the squaring detector 100. The configuration (memory 101, detection circuit 102, selection circuit 103, long code timing detection circuit 104) for that purpose is the same as that in the long code reception timing detection circuit 61 of FIG.

(Claim 13) FIG. 24 is a block diagram corresponding to claim 13, which is characterized by the long code reception timing detection circuit 105 and has another configuration, that is, the long code mask timing detection circuit 25, The operations of the long code group detection circuit 40 and the long code identification circuit 69 are the same as those in the above claims. The operation of the long code reception timing detection circuit 105 is as follows.

1. Based on the long code mask timing detected by the long code mask timing detection circuit 25, the long code timing of the long code timing fixed code spread symbol and the received spread modulated signal at the reception timing of the long code timing fixed code spread symbol The long code timing from the fixed code replica generator 94 is integrated with the fixed code.
The dump circuit 95 integrates.

2. The integration / dump circuit 97 integrates the correlation between the reception spread modulation signal at the reception timing of the long code mask symbol and the common short code from the common short code replica generator 96.

3. The correlation between the reception spread modulation signal at the reception timing of the group code spread symbol and the group code from the group code replica generator 106 is integrated /
The dump circuit 107 integrates.

4.2. And 3. The channel estimation value (complex) is detected in the channel estimation circuit 98A from the correlation integral value (complex) obtained in (1).

5.4. The complex conjugate of the channel estimation value of is multiplied by the correlation integral value (complex) of 1. to obtain the channel-compensated correlation integral value (complex).

6.1. ~ 5. Is performed at the reception timing of a plurality of long code timing fixed codes, and the obtained correlation integral value (complex) after channel compensation is averaged by a complex signal averaging circuit 99 in a complex manner.

7. The reception timing of the long code is detected using the value obtained by squaring detection of the averaged correlation integral value (complex) by the squaring detector 100. The configuration (memory 101, detection circuit 102, selection circuit 103, long code timing detection circuit 104) for that purpose is the same as that in the long code reception timing detection circuit 61 of FIG.

The claims 14 to 17 will be described below.
26 to 3 show circuits to which these can be applied.
5 to FIG. 5, and FIGS.
And the basic operation is similar to those in FIGS.

(Claim 14) FIG. 36 is a block diagram corresponding to claim 14, wherein the first long code reception timing tracking circuit 120 operates as follows.

The timing control circuit 135 is shown in FIGS.
A signal indicating the reception timing of the long code mask symbol output from any of the long code mask timing detection circuits 9, 31 to 35 is input, and the phase of the common short code generator 121 is set to the same reception timing. The common short code from the common short code generator 121 at the timing and the common short code at this timing are respectively shifted by + Δ phase and −Δ phase by the + Δ phase delay device 123 and the −Δ phase delay device 122, respectively. The correlation between the code and the reception spread modulation signal is integrated by each of the integration / dump circuits 124, 125, 126, and each of the square detectors 127, 128, 129 outputs two signals.
Multi-detection is performed and averaged by averaging circuits 130, 131 and 132, and a maximum correlation value selection circuit (comparator) 133
Select the maximum correlation value with. The long code mask symbol reception timing error detection circuit 134 determines the difference between the timing of the maximum correlation value from the maximum correlation value selection circuit 133 and the previous timing (initially, the timing of the maximum correlation value from the maximum correlation value selection circuit 133. Remains)) is detected. The timing control circuit 135 uses the timing of the maximum correlation value as a new (updated) long code mask symbol reception timing based on the detection signal from the detection circuit 134, and applies the corresponding configuration in FIGS. 26 to 29 and 31 to 35. To the common short code generator 121. 26 to 29 and 31 to 35 will be described later.

(Claim 15) FIG. 37 is a block diagram corresponding to claim 15, wherein the second long code reception timing tracking circuit 140 operates as follows.

The timing control circuit 135 is shown in FIG.
A signal indicating the reception timing of the long code mask symbol output from any one of the long code mask timing detection circuits 2 is input, and the phase of the common short code generator 121 and the phase of the group code generator 141 are set to the same reception timing. set. The group code generator 141 selects the group code corresponding to the selected group code from the maximum correlation value sum selection circuit in the long code group detection circuit of FIG. Set to the (updated) timing. The group code from the group code generator 141 at this timing is the group code from the group code generator 141 at the above timing and the group code at this timing in the + Δ phase delay device 143 and the −Δ phase delay device 142, respectively. Integrating / dumping circuits 144, 145, and the correlation between the group code of the timing shifted by + Δ phase and −Δ phase and the reception spread modulation signal.
146, respectively, and integrate and dump circuits 124 and 12
Squared detector 12 after summing with output from 5,126
Supply to 7,128,129. Averaging circuit 130, 1
Operations after 31, 132 are the same as those in FIG.

The timing control circuit 135 is the detection circuit 1
Based on the detection signal from 34, the timing of the maximum correlation value is output as the new (updated) long code mask symbol reception timing to the corresponding configuration of FIGS. 27 and 32, and the common short code generator 121, group It is set in the code generator 141. 27, 32
Will be described later.

The control circuit 147 controls the common short code generator 121 and the group code generator 1.
Either one or both of 41 can be operated, and only the correlation value between the short code and the received signal relating to the operated generator will be involved in the tracking in the tracking circuit 140. In addition, the outputs from the integration / dump circuits 144, 145, 146 and the outputs from the integration / dump circuits 124, 125, 126 are square-detected by different square-law detectors, and then added to average each other. 130,
You may make it supply to 131,132.

(Claim 16) FIG. 38 is a block diagram corresponding to claim 16, wherein the third long code reception timing tracking circuit 160 operates as follows.

The timing control circuit 135 is shown in FIGS.
A signal indicating the reception timing of the long code mask symbol output from any of the 9, 31, 33, 34, and 35 long code mask timing detection circuits is input,
The phase of the common short code generator 121 and the phase of the long code timing fixed code generator 161 are set to the same reception timing. The long code timing fixed code generator 161 uses the long code timing fixed code generator 161 shown in FIGS.
The long code timing decision code corresponding to the selected long code timing decision code from the selection circuit of the sum of the maximum correlation values in the long code group detection circuit 4 or 35 is selected, and the long code timing decision code from the timing control circuit 135 is updated. Set) timing. The group code from the long code timing confirmation code generator 161 at this timing is the + Δ phase of the long code timing confirmation code from the long code timing confirmation code generator 161 at the timing and the long code timing confirmation code at this timing. Delay device 163,
A long code timing confirmation code with a timing shifted by + Δ phase and −Δ phase by the −Δ phase delay device 162, respectively,
The integration / dump circuit 16 calculates the correlation with the reception spread modulation signal.
Integrating / dumping circuit 1
After being added to the outputs from 24, 125 and 126, they are supplied to the square wave detectors 127, 128 and 129. Averaging circuit 1
The operation after 30, 131, and 132 is the same as that of FIG.

The timing control circuit 135 is the detection circuit 1
28, 29, 31, 33, 3 as the timing of the maximum correlation value as the new (updated) long code mask symbol reception timing based on the detection signal from 34.
It outputs to the corresponding configurations of 4, 35 and is set in the common short code generator 121 and the long code timing fixed code generator 161. 28, 29, 31,
33, 34 and 35 will be described later.

It should be noted that the control circuit 167 can operate either or both of the common short code generator 121 and the long code timing fixed code generator 161, so that the short code and the received signal relating to the operated generator are generated. Only the correlation value is involved in tracking in the tracking circuit 160. Also,
The outputs from the integrating / dumping circuits 164, 165, 166 and the outputs from the integrating / dumping circuits 124, 125, 126 are square-law detected by different square-law detectors and then added to average the averaging circuit 130, You may make it supply to 131,132.

(Claim 17) FIG. 39 is a block diagram corresponding to claim 17, wherein the fourth long code reception timing tracking circuit 180 operates as follows.

The timing control circuit 135 is shown in FIG.
A signal indicating the reception timing of the long code mask symbol output from any one of the long code mask timing detection circuits 1, 33 and 35 is input, and the phase of the common short code generator 121 and the group code generator 14 are input.
The phase of 1 and the phase of the long code timing fixed code generator 161 are set to the same reception timing. Common short code generator 121, group code generator 1
41 and long code timing fixed code generator 1
The operation of 61 and the operations of the + Δ phase delay device and the −Δ phase delay device are the same as those of FIGS. 36 to 38, but the long code timing fixed code generator 161 is similar to that of FIGS.
From the timing control circuit 135, a long code timing fixed code corresponding to the selected long code timing fixed code from the selection circuit for the sum of the maximum correlation values in the long code group detection circuit 1, 33, or 35 is selected. Set to the (updated) timing of. Further, the group code generator 141 selects a group code corresponding to the selected group code from the selection circuit for the sum of maximum correlation values in the long code group detection circuit of FIG. The timing is updated (updated) from the timing control circuit 135.

The operation after averaging circuits 130, 131 and 132 is the same as that of FIG.

The timing control circuit 135 is the detection circuit 1
Based on the detection signal from 34, the timing of the maximum correlation value is output as the new (updated) long code mask symbol reception timing to the corresponding configuration of FIGS. 30, 31, 33, and 35, and the common short code is generated. It is set in the device 121, the group code generator 141, and the long code timing fixed code generator 161. Figure 3
0, 31, 33, and 35 will be described later.

The control circuit 187 controls the common short code generator 121 and the group code generator 141.
And long code timing fixed code generator 161
Any one or two or all of them can be operated, and only the correlation value between the short code regarding the operated generator and the received signal is involved in the tracking in the tracking circuit 180. The outputs from the integration / dump circuits 164, 165, 166, the outputs from the integration / dump circuits 144, 145, 146, and the outputs from the integration / dump circuits 124, 125, 126 are different square-law detectors. After square-law detection at, add and average circuit 13
0, 131, 132 may be supplied.

(Claims 18 to 26) FIGS. 26 to 35 are block diagrams corresponding to claims 18 to 26, and the basic operation thereof is as described in FIGS. 15 to 24, and each replica generator. The updated long code mask symbol reception timings from the timing control circuits of FIGS. Which of the parallel inputs is adopted is controlled by a control circuit (not shown). By using the updated long code mask symbol reception timing, even if there is a clock difference between the transmitter and the receiver, true synchronization timing can be obtained, and spread code synchronization accuracy and speed deterioration is effectively prevented. To be done.

(Claims 27 and 28) FIG.
It is a block diagram corresponding to 7,28. Basically, Figure 1
4 is the same as the code spreading processing portion of the downlink channel transmitter in the cellular base station as an embodiment of the code spreading method of the mobile communication system to which the present invention is applied, but masks the long code for the control channel. The common short code of the part is the common short code 2 generation unit 11
It is supplied from B through the switch 24B and added with the group code and the long code timing confirmation code,
The common short code of the other portion is supplied from the common short code 1 generation unit 11A via the switch 24A and added to each of the other short codes by the adder 20A.

With this structure, the following effects are produced. That is, since the transmission signal from the base station can synchronize each channel as in this configuration, orthogonality between the channels can be realized by using the orthogonal code sequence for the short code. Orthogonal Gold code sequences, Walsh code sequences, etc. are generally well known as orthogonal sequences,
Here, the orthogonal Gold code has a relatively excellent autocorrelation property (has an impulse-shaped autocorrelation property), but W
The auto-correlation characteristic of the ald code often produces 1 and is caused by the CDM.
Not suitable for A. However, in practice, a short code is multiplied by a long code, which is a random sequence with a very long period, to form a spreading code, and as a result, an orthogonal Gol is obtained.
Regardless of whether the d code is used or the Walsh code is used, the autocorrelation characteristics of the spreading code after being multiplied by the long code are almost similar to those of the impulse. Where W
When the present invention is applied with the ash code as a short code, the correlation characteristic of the code in the signal in which the long code is masked deteriorates, and the timing of the long code mask cannot be detected accurately. For this reason, when masking a long code, for example, the short code is changed to a code having excellent autocorrelation characteristics such as an orthogonal Gold code or an M sequence, and the receiver also detects correlation using the orthogonal Gold code (or M sequence) as a replica code. It is possible to improve the timing detection accuracy of the long code mask by detecting the correlation peak by performing.

In the above example, the common short code 1 in FIG. 40, the communication channel (1) short code,
..., the Wa1sh sequence is used for each generation unit of the communication channel (N) short code, and the orthogonal Gold sequence or M sequence is used for the common short code 2 generation unit. When using a group code or a long code timing fixed code, either sequence can be used. In the above description, the combination of the Walsh code and the orthogonal Gold code (or the M sequence) has been described, but it is also possible to easily analogize to applying the combination of other codes. As described above, even if the Walsh code sequence is used, the short code when masking the long code is orthogonal G
By using a code having excellent autocorrelation characteristics such as an old code or an M sequence, it is possible to contribute to improvement in timing detection accuracy of the long code mask on the receiving side.

[0184]

As described above, according to the present invention,
High-speed and highly accurate initial synchronization (cell search) can be achieved in cellular communication using DS-CDMA.

[Brief description of drawings]

FIG. 1 is a diagram showing an algorithm of a spread code synchronization system in the invention of the prior application.

FIG. 2 is a diagram showing a frame structure of a spread modulation method in the invention of the prior application.

FIG. 3 is a diagram showing a block configuration of a matched filter.

FIG. 4 is a diagram showing a block configuration of a sliding correlator.

FIG. 5 is a diagram showing a search method of long code initial synchronization in the invention of the prior application.

FIG. 6 is a diagram showing an operation example of claim 1 of the present invention.

FIG. 7 is a diagram showing an operation example of claim 2 of the present invention.

FIG. 8 is a diagram showing an example of a transmission frame structure according to claims 3, 4, and 5 of the present invention.

FIG. 9 is a diagram showing an example of a transmission frame structure according to claim 7 of the present invention.

FIG. 10 is a diagram showing an operation example of claim 6 of the present invention.

FIG. 11 is a diagram showing an operation example of claim 8 of the present invention.

FIG. 12 is a diagram showing an operation example of claim 9 of the present invention.

FIG. 13 is a diagram showing an operation example of claims 10, 11, 12, and 13 of the present invention.

FIG. 14 is a block diagram corresponding to each claim of the present invention.

FIG. 15 is a block diagram corresponding to claim 1 of the present invention.

FIG. 16 is a block diagram corresponding to claim 2 of the present invention.

FIG. 17 is a block diagram corresponding to claim 6 of the present invention.

FIG. 18 is a partial block diagram corresponding to claim 8 of the present invention.

FIG. 19 is a remaining block diagram corresponding to claim 8 of the present invention.

FIG. 20 is a block diagram corresponding to claim 9 of the present invention.

FIG. 21 is a block diagram corresponding to claim 10 of the present invention.

FIG. 22 is a block diagram corresponding to claim 11 of the present invention.

FIG. 23 is a block diagram corresponding to claim 12 of the present invention.

FIG. 24 is a block diagram corresponding to claim 13 of the present invention.

FIG. 25 is a diagram showing an example of basic operation according to claims 14 to 17 of the present invention.

FIG. 26 is a block diagram corresponding to claim 18 of the present invention.

FIG. 27 is a block diagram corresponding to claim 19 of the present invention.

FIG. 28 is a block diagram corresponding to claim 20 of the present invention.

FIG. 29 is a partial block diagram corresponding to claim 21 of the present invention.

FIG. 30 is a remaining block diagram corresponding to claim 21 of the present invention;

FIG. 31 is a block diagram corresponding to claim 22 of the present invention.

FIG. 32 is a block diagram corresponding to claim 23 of the present invention.

FIG. 33 is a block diagram corresponding to claim 24 of the present invention.

FIG. 34 is a block diagram corresponding to claim 25 of the present invention.

FIG. 35 is a block diagram corresponding to claim 26 of the present invention.

FIG. 36 is a block diagram corresponding to claim 14 of the present invention.

FIG. 37 is a block diagram corresponding to claim 15 of the present invention.

FIG. 38 is a block diagram corresponding to claim 16 of the present invention.

FIG. 39 is a block diagram corresponding to claim 17 of the present invention.

FIG. 40 is a block diagram corresponding to claims 27 and 28 of the present invention.

[Explanation of symbols]

25 Long code mask timing detection circuit 34-channel estimation circuit 35 Data judgment circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Ohno 2-10-1 Toranomon, Minato-ku, Tokyo NTT Mobile Communication Network Co., Ltd. (72) Inventor Toyoyo Higashi Toranomon, Minato-ku, Tokyo 2-10-1 NTT Mobile Communication Network Co., Ltd. (56) References International Publication 97/33400 (WO, A1) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04B 7/24-7/26 H04Q 7/00-7/38

Claims (28)

(57) [Claims] 1. A direct spread C which spreads a signal to a wide band signal by a spreading code having a speed higher than an information rate and transmits the signal.
In the DMA communication system, a short-period spreading code group common to each base station having a repetition period of an information symbol period and a long-period spreading code group different for each base station having a longer repetition period compared to the information symbol period are used. A double-spread with the first short-cycle spreading code of the short-cycle spreading code group and the long-cycle spreading code of the long-cycle spreading code group, and receives a signal in which the long-cycle spreading code is masked at a constant cycle, With respect to the reception spread modulation signal obtained by the reception,
A correlation detection value of a code obtained by multiplying the long-cycle spreading code of the long-cycle spreading code group by the first short-cycle spreading code and the received spread-modulation signal is detected over a plurality of short-cycle spreading code periods, and the detected correlation detection value is obtained. At the time position where the maximum correlation output signal of the first short-cycle spreading code and the reception spreading-modulation signal is obtained when detecting the long-cycle spreading code that spreads the received signal from the averaged and averaged correlation detection values Propagation path estimation is performed using a despread signal as a reference signal, and a code obtained by multiplying a long period spreading code between each of the short period spreading code periods by a first short period spreading code using the propagation channel estimated value, and a reception spreading modulation signal. And a data modulation component included in a correlation output of the received spread modulation signal and a code obtained by multiplying the long-cycle spreading code between the short-cycle spreading code periods by the first short-cycle spreading code and the received spreading-modulation signal. Data modulation And channel spreading code synchronization method characterized by averaging the in-phase addition of the correlation output value obtained by removing the phase rotation due to fluctuations. 2. The signal according to claim 1, further comprising: receiving a signal spread in a burst at a known timing with a second short-cycle spreading code according to the type of long-cycle spreading code used in each base station, and transmitting the signal. The path estimation is obtained by despreading the despread signal at the time position at which the maximum correlation output signal of the first short cycle spreading code and the received spread modulated signal is obtained and the signal spread by the second short cycle spreading code. Spread code synchronization method, characterized in that at least one of the generated signals is performed as a reference signal. 3. A direct spread C which spreads a signal to a wide band signal by a spreading code having a speed higher than an information rate and transmits the signal.
In the DMA communication system, a short-period spreading code group common to each base station having a repetition period of an information symbol period and a long-period spreading code group different for each base station having a longer repetition period compared to the information symbol period are used. And masking the long-period spreading code,
When transmitting a signal in which the number of times of transmitting the signal spread only by the short period spreading code is n times with respect to the long period spreading code period L, and the period is a period L / n at equal intervals, Furthermore, the signal transmission method is characterized in that a signal spread by a third short-cycle spreading code indicating a timing of transmitting the head part of the long-cycle spreading code is transmitted at a known timing in a burst manner. 4. The third short-cycle spreading code according to claim 3, which indicates the timing of transmitting the head of the long-cycle spreading code, sets the timing of transmitting the head of the long-cycle spreading code according to the pattern of the code to be transmitted. A method of transmitting a signal, characterized in that 5. The third short-cycle spreading code indicating the timing of transmitting the head of the long-cycle spreading code according to claim 3, represents the timing of transmitting the head of the long-cycle spreading code according to the timing of transmission. A method of transmitting a signal, characterized in that 6. The transmission signal according to any one of claims 3 to 5 is received, and the correlation between the received signal and the first short-cycle spreading code is calculated by the period L /
From the timing of observing at n and obtaining the maximum correlation value, the timing of receiving the signal spread only by the first short cycle spreading code is detected, and the signal spread only by the obtained first short cycle spreading code. From the reception timing of the third short-cycle spreading code indicating the timing of transmitting the head part of the long-cycle spreading code, the reception signal and the third short-cycle are received at the reception timing of the third short-cycle spreading code. The reception timing of the long-cycle spreading code is detected from the correlation output value by performing correlation detection processing with the cycle-spreading code, and at the reception timing of the long-cycle spreading code, the received signal and each long-cycle spreading code of the long-cycle spreading code group And a code obtained by multiplying the first short-cycle spreading code by correlation detection processing to detect a long-cycle spreading code for spreading the received signal from the correlation output value. Law. 7. The method according to claim 3, further comprising transmitting a signal spread by a second short-cycle spreading code according to the type of the long-cycle spreading code at a known timing in a burst manner. Characteristic signal transmission method. 8. The transmission signal according to claim 7 is received, and the correlation between the received signal and the first short-cycle spreading code is calculated by the period L /
From the timing of observing at n and obtaining the maximum correlation value, the timing of receiving the signal spread only by the first short cycle spreading code is detected, and the signal spread only by the obtained first short cycle spreading code. From the reception timing of the third short-cycle spreading code indicating the timing of transmitting the head part of the long-cycle spreading code, the reception signal and the third short-cycle are received at the reception timing of the third short-cycle spreading code. The timing for detecting the reception timing of the long cycle spreading code from the correlation output value by performing the correlation detection processing with the cycle spreading code, and the timing for receiving the signal spread by only the obtained first short cycle spreading code or the long cycle spreading code. From the reception timing of the signal, the reception timing of the signal spread by the second short cycle spreading code is detected, and the reception timing of the signal spread by the second short cycle spreading code is detected. The second short-cycle spreading code and the received signal are subjected to correlation detection processing to detect a long-cycle spreading code group including the long-cycle spreading code for spreading the received signal from the correlation output value, and the reception timing of the long-cycle spreading code. In, the correlation output is performed by performing a correlation detection process between each long-cycle spreading code of the long-cycle spreading code group including the long-cycle spreading code that spreads the received signal and the detected reception signal, and the code multiplied by the first short-cycle spreading code. A spread code synchronization method characterized by detecting a long period spread code for spreading a received signal from a value. 9. The method according to claim 1 or 2, wherein the transmission signal according to any one of claims 3, 4, 5 and 7 is received, and a maximum correlation output signal between the first short period spreading code and the reception spread modulation signal is output. A signal obtained by despreading the despread signal at the obtained time position and the signal spread by the second short cycle spreading code and a signal obtained by despreading the signal spread by the third short cycle spreading code. Of at least one of the two as a reference signal, and using the channel estimation value, a code obtained by multiplying a long period spreading code between each of the short period spreading code periods by a first short period spreading code, and reception spreading modulation. A data modulation component included in a correlation output with a signal is detected and included in a correlation output between a code obtained by multiplying a long-cycle spreading code between each short-cycle spreading code period and a first short-cycle spreading code and a reception spreading-modulation signal. Data modulation components and propagation Averages the correlation output value obtained by removing the phase rotation due to fluctuation by in-phase addition, the spreading code synchronization method characterized by detecting a long period spreading code for spreading the received signal from the averaged correlation output value. 10. In a direct sequence CDMA communication system for transmitting a signal by expanding a band into a wide band signal by a spreading code having a speed higher than an information rate, a short cycle common to each base station having a repetition cycle of an information symbol cycle. A first short-cycle spreading code and a long-cycle spreading code of the short-cycle spreading code group using a spreading code group and a long-cycle spreading code group that is different for each base station having a longer repetition period than the information symbol cycle. A signal that is doubly spread with a long-cycle spreading code of a group and is masked with the long-cycle spreading code at a constant cycle, and further with a second short-cycle spreading code according to the type of the long-cycle spreading code used in each base station. A signal spread in a burst at a known timing is received, and a first signal is received from the received spread signal obtained by the reception.
The reception timing of the signal spread by the second short cycle spreading code is detected from the timing of receiving the signal spread by only the short cycle spreading code or the reception timing of the long cycle spreading code, and at this timing, the second short cycle is detected. The correlation detection process between the spreading code and the received signal is performed a plurality of times to average the correlation detection values between the second short cycle spreading code and the received signal, and the long period spreading for spreading the received signal from the averaged correlation detection value. When detecting a long-cycle spreading code group including a code, channel estimation is performed using a despread signal at a time position at which the maximum correlation output signal of the first short-cycle spreading code and the received spread modulation signal is obtained as a reference signal. , A phase rotation amount associated with channel fluctuation included in a correlation detection output between the second short-cycle spreading code and the received signal is detected using the channel estimation value, and the second short-cycle spreading code is detected. Spreading code synchronization method characterized by averaging the in-phase addition of the correlation output value obtained by removing the phase rotation due to the propagation path fluctuation included in the correlation detection output of the signal signal. 11. The time for obtaining the maximum correlation output signal of the first short-period spreading code and the reception spread modulation signal in the propagation path estimation when receiving the transmission signal according to claim 7. A spreading code synchronization method characterized in that at least one of a despread signal at a position and a signal obtained by despreading the signal spread by the third short cycle spreading code is used as a reference signal. 12. The spread signal is spread by the third short-cycle spreading code from the timing of receiving the transmission signal of any one of claims 3, 4, and 5 and receiving the signal spread only by the first short-cycle spreading code. The reception timing of the received signal is detected, the correlation detection processing between the third short-cycle spreading code and the reception signal is performed a plurality of times at this timing, and the correlation detection values between the third short-cycle spreading code and the reception signal are averaged. When detecting the reception timing of the long cycle spreading code from the averaged correlation detection value, the reference signal is the despread signal at the time position where the maximum correlation output signal of the first short cycle spreading code and the reception spread modulated signal is obtained. As a result, the channel estimation is performed, and the amount of phase rotation accompanying the channel fluctuation included in the correlation detection output between the third short-cycle spreading code and the received signal is detected using the channel estimation value. Diffusion mark Spreading code synchronization method characterized by averaging the in-phase addition of the correlation output value obtained by removing the phase rotation due to the propagation path fluctuation included in the correlation detection output of the received signal and. 13. The method according to claim 12, wherein the transmission signal according to claim 7 is received, and the propagation path estimation is performed at a time position at which a maximum correlation output signal of the first short period spreading code and the reception spread modulation signal is obtained. A spreading code synchronization method, wherein at least one of a despread signal and a signal obtained by despreading the signal spread by the second short cycle spreading code is used as a reference signal. 14. A direct sequence CDMA communication system for transmitting a signal by expanding a band into a wide band signal by a spreading code having a speed higher than an information rate, and a short cycle common to each base station having a repetition cycle of an information symbol cycle. A first short-cycle spreading code and a long-cycle spreading code of the short-cycle spreading code group using a spreading code group and a long-cycle spreading code group that is different for each base station having a longer repetition period than the information symbol cycle. A signal which is doubly spread with a long-period spreading code of a group and which is spread with only the first short-period spreading code at a constant period is received, and with respect to a reception spread modulation signal obtained by the reception,
A correlation detection value of a code obtained by multiplying the long-cycle spreading code of the long-cycle spreading code group by the first short-cycle spreading code and the received spread-modulation signal is detected over a plurality of short-cycle spreading code periods, and the detected correlation detection value is obtained. When the long-cycle spreading code that spreads the received signal is detected from the averaged and averaged correlation detection values, the correlation between the received signal and the first short-cycle spreading code is detected, and the correlation detection is performed. A first timing for receiving a signal spread only by the first short cycle spreading code is detected based on the magnitude of a correlation value, and the received signal and the first short cycle spreading code are detected at the detected first timing. Correlation detection with Δ phase (Δ phase is a
Corresponding to Tc: a is a real number, Tc is a chip period, and the timing is shifted, and based on the magnitude of the correlation value at each timing,
A spreading code synchronization method, characterized in that the first timing is updated. 15. The signal according to claim 14, further comprising: receiving a signal spread in a burst at a known timing with a second short-cycle spreading code according to the type of the long-cycle spreading code used in each base station. A spreading code synchronization method, wherein when detecting the timing 1, the correlation between the received signal, the first short cycle spreading code and the second short cycle spreading code is detected. 16. The signal according to claim 14, further comprising: receiving a signal spread at a known timing in a burst manner with a third short-cycle spreading code that indicates a timing of transmitting the head part of the long-cycle spreading code. When detecting the timing of, the spread code synchronization method is characterized in that the correlation between the received signal, the first short-cycle spreading code, and the third short-cycle spreading code is detected. 17. The signal according to claim 15, further comprising: receiving a signal spread in burst at a known timing with a third short-cycle spreading code indicating a timing of transmitting the head part of the long-cycle spreading code, The spread code synchronization method is characterized in that the correlation between the received signal, the first short-cycle spreading code, the second short-cycle spreading code, and the third short-cycle spreading code is detected when the timing is detected. 18. The spreading code synchronization method according to claim 1
4. A spreading code synchronization method characterized in that the spreading code synchronization method of 4 is applied. 19. The spread code synchronization method according to claim 2
5. A spread code synchronization method characterized in that the spread code synchronization method of No. 5 is applied. 20. The spread code synchronization method according to claim 6, wherein
A spreading code synchronization method, wherein at least one spreading code synchronization method of 4 and 16 is applied. 21. The spread code synchronization method according to claim 8, wherein
A spread code synchronization method, wherein at least one spread code synchronization method of 4, 16 and 17 is applied. 22. The spread code synchronization method according to claim 9,
A spread code synchronization method, wherein at least one spread code synchronization method of 4, 16 and 17 is applied. 23. A spread code synchronization method characterized by applying at least one spread code synchronization method according to claim 14 to the spread code synchronization method according to claim 10. 24. A spread code synchronization method characterized by applying at least one spread code synchronization method according to claim 14, 16 or 17 to the spread code synchronization method according to claim 11. 25. A spread code synchronization method characterized by applying at least one spread code synchronization method according to claim 14 to the spread code synchronization method according to claim 12. 26. A spread code synchronization method characterized by applying at least one spread code synchronization method of claim 14 to the spread code synchronization method of claim 13. 27. In a direct sequence CDMA communication system for transmitting a signal by expanding a band into a wide band signal by a spreading code at a speed higher than an information rate, a short cycle common to each base station having a repetition cycle of an information symbol cycle. A first short-cycle spreading code and a long-cycle spreading code of the short-cycle spreading code group using a spreading code group and a long-cycle spreading code group that is different for each base station having a longer repetition period than the information symbol cycle. When the signal is transmitted by being double-spread with the long-period spreading code of the group, the long-period spreading code is masked at a constant period,
A signal transmission method in a mobile communication system, which transmits a signal spread only by a short period spreading code different from the first short period spreading code and having an autocorrelation characteristic superior to that of the first short period spreading code. 28. The spread code synchronization method according to claim 14, wherein the signal transmitted by the signal transmission method according to claim 27 is received.