JP2001103024A - Digital wireless device, digital wireless communication system, digital wireless transmitting device, digital wireless communication method - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To enable reception of a plurality of channels without increasing hardware. A demodulation unit 720 is configured by a digital signal processor or the like, performs filter operation processing on digital data of two channels subjected to baseband conversion by quadrature detectors 713 and 715, and performs channel selection and symbol identification. Detect points. Then, a demodulation process is executed to extract data at the symbol identification point and demodulate data for two channels.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a digital radio apparatus, a digital radio communication system, a digital radio transmission apparatus, and a digital radio communication method.

[0002]

2. Description of the Related Art In recent years, frequency resources have been depleted due to the expansion of radio wave application fields and diversification of needs. On the other hand, demand for mobile communication has been increasing, and higher speed communication is also required.

In order to solve these problems, digitalization of wireless communication has been promoted, and various digital communication systems have been proposed. Also, the hardware configuration of the wireless communication device, which is configured by an analog circuit, is being digitized.

In mobile communication, a multi-rate mobile radio communication system capable of transmitting and receiving information between a mobile station and a base station at a plurality of transmission rates using a plurality of lines in one carrier by a transmitting / receiving device in the base station. A system has been proposed. A control station that controls a base station in this system includes:
It has been proposed to determine whether there is a free line according to the transmission rate capability of a mobile station that has made a call request, and to select a free line and to perform line allocation when there is a free line.

[0005]

Conventionally, in a wireless communication system operated in a multi-access system using a plurality of channels, the bandwidth and transmission rate of each channel are fixed. Therefore, when traffic is small, there is a problem that an empty frequency band exists and the frequency use efficiency is reduced.

In order to solve such a problem, multi-rate communication has been proposed in a time division communication system (TDMA) or the like. However, the maximum bandwidth that can be used in one communication is limited by the bandwidth of a carrier used. For that reason, multi-rate communication could not be performed by the FDMA method with one carrier and one channel.

[0007] Also, there have been proposed methods of allocating appropriate radio resources according to traffic, but these methods cannot change the band at any time. An object of the present invention is to enable communication with different bandwidths without changing hardware. Another problem is to enable multi-rate communication using a plurality of channels. Still another object is to provide a diversity effect without providing a plurality of wireless circuits.

[0008]

1 (A) and 1 (B) show a first embodiment of the present invention.
FIG. 3 is an explanatory view of the principle of the invention described in claims 1 and 2; According to the first aspect of the present invention, a receiving unit that receives a plurality of channels of radio signals divided on a frequency axis, and converts the plurality of channels of radio signals received by the receiving unit into an intermediate frequency signal or a baseband signal, respectively. A plurality of conversion means; and a calculation means for independently demodulating a plurality of intermediate frequency signals or baseband signals converted by the plurality of conversion means by digital calculation processing.

According to a second aspect of the present invention, there is provided a receiving section 1 for receiving a plurality of channels of radio signals divided on a frequency axis, and transmitting the plurality of channels of radio signals received by the receiving section to an intermediate frequency signal or an intermediate frequency signal, respectively. An arithmetic unit 4 for performing digital arithmetic processing for converting into a baseband signal and independently demodulating a plurality of intermediate frequency signals or baseband signals.

According to the first and second aspects of the present invention, when receiving and demodulating radio signals of a plurality of channels divided on the frequency axis, an RF receiving unit and a hardware modulation circuit for the number of channels, or Since it is not necessary to have a detection circuit and a modulation circuit, the hardware circuit of the digital wireless device is simplified, and the device can be downsized.

The arithmetic means 4 has, for example, a communication speed changing means for changing a communication speed by using an arbitrary number of channels among a plurality of channels for one communication. This makes it possible to transmit and receive data at a higher speed by simultaneously using a plurality of channels for one communication.

Further, signal quality detecting means for detecting the quality of the signal of each channel, and selecting / synthesizing means for selecting signals of a plurality of channels based on the detection result of the signal quality detecting means or synthesizing the signals. May be provided. Thereby, when the same data is transmitted using a plurality of channels, communication quality can be further improved by selecting a signal of a channel with good signal quality or combining signals of a plurality of channels.

The receiving section 1 converts the signals of a plurality of channels into intermediate frequency signals so that the intermediate frequency signals of the plurality of channels fall within the pass band of the same intermediate frequency filter.
A plurality of local oscillation units having oscillation frequencies corresponding to the frequencies of the respective channels may be provided.

Thus, even when the frequency interval between the respective channels is larger than the pass band width of the intermediate frequency filter, the signals of a plurality of channels can be passed through one intermediate frequency filter and demodulated by digital arithmetic processing. Can be.

An invention according to claim 18 is a digital radio communication system in which a signal from a mobile station of a communication partner is transmitted back at a base station, wherein the mobile station includes a radio signal receiving section and a radio signal receiving section. A plurality of detecting means for respectively detecting the received radio signals of the plurality of channels, an arithmetic means for independently demodulating the detected signals of the plurality of channels by digital arithmetic processing, or a radio signal receiving section and a radio signal receiving section. Operating means for independently detecting and demodulating the radio signals of the plurality of channels by digital operation processing, receiving a signal from a partner mobile station on one of the plurality of channels, and receiving a signal from a base station on another channel. Signal quality detecting means for detecting the signal quality of each channel when simultaneously receiving the signals from the turned-back partner mobile station; And a selection / combining means for selecting / combining the folded signal by the signal and the base station from the other mobile station on the basis of the stage of the detection result.

According to the present invention, a signal directly transmitted from a partner mobile station and a signal of the partner mobile station looped back by the base station are simultaneously received, and a signal having good signal quality is selected or By combining these signals, reliable communication quality can be ensured.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a diagram illustrating a basic configuration of the digital wireless device according to the embodiment.

From the radio signal received by the antenna 201, a high-frequency signal is extracted by a high-frequency band-pass filter 202, amplified by a high-frequency amplifier 203, and
04, the first local oscillator 205 generates the first
The signal is mixed with the local oscillation signal and converted into a first intermediate frequency signal.

The first intermediate frequency signal passes through an intermediate frequency filter 206, and is mixed with a second local oscillation signal generated by a second local oscillator 208 in a next stage mixing section 207 to form a second intermediate frequency signal. Is converted. The second intermediate frequency signal passes through a second intermediate frequency filter 209, is converted into a digital signal by an A / D converter 210, and is output to two orthogonal transform units 212 and 213. Oscillator 211 is A / D
This is a circuit for generating a sampling clock of the converter 210.

The quadrature detectors 212 and 213, the Nyquist filters 214 and 215, and the extraction unit 216 are realized by digital processing such as a digital signal processor (DSP). The quadrature detectors 212 and 213 are circuits for extracting an I channel signal and a Q channel baseband signal from a carrier wave, and the Nyquist filters 214 and 215 determine the frequency Fc of the quadrature modulation signal output from the quadrature detector 212.213. This is a bandpass filter having a center frequency and a bandwidth Bw. Further, the extracting unit 216 extracts digital data before modulation from the demodulated baseband signal.

FIG. 3 shows the reception signal band-limited by the band-pass filter 202 and the first intermediate frequency signal. The frequency of the first local oscillation signal is set so that signals of two channels fall within the pass band of the same intermediate frequency file.

FIG. 4 shows a second intermediate frequency signal and its second
2 shows a baseband signal obtained by orthogonal detection of an intermediate frequency signal. FIG. 5 is a diagram illustrating a configuration of the quadrature detection unit. FIG. 5 shows that the quadrature detectors 212 and 213 are constituted by hardware circuits, and the Nyquist filters 214 and 21 are used.
5 shows a circuit configuration when a digital signal processor 5 is used.

The modulated carrier is Re [U (t) exp ｛j
(2πFc · t + φ}], where “Re []” indicates that [] is a real part, and φ indicates the phase difference of the carrier.

When the modulated carrier waves of two channels are input to the quadrature detector of FIG.
1, 502, and the mixers 503, 504, 50
5, 506. Then, in the mixer 503, the frequency F generated by the first carrier signal generator 507 is output.
The first carrier signal a is mixed to extract an I-channel baseband signal Ia (t). Also, the mixer 504
In, the first carrier signals whose phases are shifted by 90 degrees by the 90-degree phase shifter 508 are mixed to extract the baseband signal jQa (t) of the Q channel. Extracted I
The channel and Q channel baseband signals are output to AD converters 509 and 510, respectively.

In the mixers 505 and 506 as well, the second carrier signal of the frequency Fb generated by the second carrier signal generator 511 and the second carrier signal whose phase is shifted by 90 degrees by the 90 degree phase shifter 512 are respectively converted. The baseband signals of the I channel and the Q channel are extracted by being mixed with the modulated carrier signal, and output to the AD converters 513 and 514.

AD converters 509, 510, 513, 51
The digital signal output from 4 is subjected to the root Nyquist filter operation processing independently by the digital signal processor 515, and a symbol identification point having no intersymbol interference is detected. The detection of the symbol identification point is performed by synchronously adding the envelope of the signal having the Nyquist characteristic after the calculation of the root Nyquist filter for each sample point, and obtaining the sample point having the peak value. This sample point becomes the symbol identification point. Then, digital information of a plurality of channels is extracted using the data of the symbol identification points.

That is, when a signal of a plurality of channels is received, a plurality of Nyquist filter operation processes are independently executed by a digital signal processor, so that a hardware filter circuit is not provided for each channel and a signal of a plurality of channels is provided. Can be demodulated. This simplifies the circuit configuration of the hardware of the digital wireless device, so that the transmitter and the receiver can be downsized.

An embodiment of the present invention will be described below with reference to a digital service radio system including one or a plurality of base stations and a plurality of mobile stations as an example. FIG. 6 shows the first embodiment of the present invention.
It is a figure showing composition of a business radio system of an embodiment. In this wireless system, a base station 601 is
The mobile station 602 transmits information such as voice, facsimile and the like using the plurality of channels F1 and F2.
It has the function of simultaneously receiving and demodulating the F2 signal.

FIG. 7 is a diagram showing the configuration of the receiving unit of the digital radio circuit of the mobile station 602. High frequency filter 70
Reference numerals 2 and 704 denote bandpass filters that use the frequency of a carrier (carrier 1 and carrier 2) transmitted from the base station 601 as a pass band, as shown in FIG. The signal received by antenna 701 is
The band is limited by the high frequency filter 702, amplified by the amplifier 703 without distortion, and output to the mixer 705. The band is limited by the high-frequency filter 702 in order to prevent an unnecessary signal from being input to the next-stage amplifier 703 and causing distortion in the amplifier 703.

The mixer 705 mixes a local oscillation signal generated by the first local oscillator 706 with a carrier and converts the signal into a first intermediate frequency signal. In the mixer 705, for example, 400.000 MHz transmitted from the base station 601
Carrier 1 of 400.025 MHz
The signals are converted into intermediate frequency signals of 10.000 MHz and 10.025 MHz, respectively.

As shown in FIG. 7, the first intermediate frequency filter 707 is a band-pass filter having the intermediate frequency of the carriers 1 and 2 as the center frequency.
The intermediate frequency signal that has passed through the first intermediate frequency filter 707 is amplified by an intermediate frequency amplifier 708, mixed in a mixer 709 with a local oscillation signal generated by a second local oscillator 710, and converted to a second intermediate frequency. The second intermediate frequency filter 711 is a band-pass filter having the second intermediate frequency as a center frequency.
The signal passing through 11 is amplified by a second intermediate frequency amplifier 712 and output to quadrature detectors 713 and 715 for two channels.

The quadrature detector 713 outputs the first carrier signal (for example, 45) generated by the first carrier signal generator 717 '.
The signal of 5.000 KHz) is mixed with the second intermediate frequency signal to extract an I channel baseband signal Ich of the carrier 1. Further, the carrier signal obtained by shifting the phase of the first carrier signal by 90 degrees by the π / 4 phase shifter 717 is mixed with the second intermediate frequency signal to form a baseband signal Qch of the Q channel.
Is extracted. Then, the I-channel and Q-channel baseband signals Ich and Qch are supplied to the A / D converters 718 and 71, respectively.
At 9, each is converted into a digital signal and output to the demodulation unit 720.

Similarly, the quadrature detector 715 mixes the second carrier signal (for example, a signal of 480.000 KHz) generated by the second carrier signal generator 721 with the second intermediate frequency signal, and The baseband signal of the I channel is extracted. Further, the π / 2 phase shifter 722
The second carrier signal whose phase is shifted by a degree is mixed with the second intermediate frequency signal to extract the baseband signal of the Q channel of carrier 2. The I-channel and Q-channel baseband signals Ich and Qch are supplied to the A / D converter 72, respectively.
The signal is converted into a digital signal at 3, 724 and output to the demodulation unit 720.

The demodulation section 720 is constituted by a digital signal processor or the like, performs root Nyquist filter arithmetic processing on the two-channel digital data orthogonally transformed by the orthogonal detectors 713 and 715, selects a channel, and selects an adjacent channel. At the same time as removing the channel, a symbol identification point is detected. Then, a demodulation process is executed to extract data at the symbol identification point and demodulate data for two channels. In FIG. 7, a plurality of root Nyquist filter operations and demodulation operations performed independently on the baseband signals of the respective channels are respectively performed by a root Nyquist filter operation unit 725 and a demodulation processing unit 726.
It is shown as

Although the transmitting circuit is not shown in FIG. 7, the transmitting circuit basically has the same configuration as the receiving circuit, and the modulating section of the transmitting circuit is composed of a digital signal processor. A Nyquist filter calculation process is performed on the baseband signal by the modulation unit. Further, the baseband signal is modulated by a plurality of quadrature modulators with a carrier of a corresponding channel, converted into a radio signal by a transmission unit including a DA converter, an amplifier, and the like, and transmitted from an antenna.

In the first embodiment, a quadrature detector 71
The demodulation unit 720 performs a root Nyquist filter operation on the baseband signals for two channels demodulated in 3, 715 by digital operation processing, so that it is not necessary to provide hardware demodulation circuits for the number of channels. As a result, communication can be simultaneously performed between the base station and the mobile station or between the mobile station using a plurality of channels, and the hardware configuration of the transmission / reception circuit is simplified, so that the transmitter and the receiver can be downsized. Further, the transmission rate can be changed by using an arbitrary number of channels among a plurality of channels for one communication. Then, by changing the transmission rate according to the communication traffic, it is possible to use the radio resources efficiently and perform communication at an optimum communication speed.

Next, FIGS. 8 and 9 show quadrature detection and root Nyquist filter calculation at the time of reception by the digital radio apparatus.
FIG. 13 is an explanatory diagram of the processing of the demodulation unit 801 and the modulation unit 901 according to the second embodiment of the present invention in which quadrature modulation and root Nyquist filter calculation at the time of transmission are performed by digital calculation processing.

In FIG. 8, a two-channel intermediate frequency signal F having frequencies Fa and Fb output from the intermediate frequency amplifier is provided.
a and Fb are converted into digital signals by the AD converter 802 and output to the demodulation unit 801. The demodulation unit 801 is configured by a digital signal processor, and outputs the intermediate frequency signals Fa,
Fb undergoes quadrature detection, and further performs a root Nyquist filter operation to convert the Fb into I-channel and Q-channel baseband signals Ich and Qch. Further, digital data before modulation is extracted from the I-channel and Q-channel baseband signals.

The modulator 901 shown in FIG. 9 is also constituted by a digital signal processor, and converts digital data to be transmitted from an I channel, a Q channel baseband signal Ich,
Qch is generated and its baseband signals Ich, Qc
h is subjected to a root Nyquist filter processing operation. Then, quadrature modulation processing is performed on each of the two channel signals on which the root Nyquist filter processing has been performed, and D
Output to A converter 902.

FIG. 10 is a diagram showing an example of the configuration of the receiving circuit according to the second embodiment. 10, the same blocks as those in FIG. 7 are denoted by the same reference numerals, and description thereof will be omitted. Hereinafter, in the description of the receiving circuit of the other embodiments, the description of the same blocks as those in FIG. 7 will be omitted.

The intermediate frequency signal amplified by the second intermediate frequency signal amplifier 712 is sampled by the AD converter 1001 at a timing synchronized with the clock generated by the sampling clock generator 1002 and converted into digital data. .

Next, in the demodulation section 1003, quadrature detection processing is performed on the digital signals of the respective channels to convert them into baseband signals Ich and Qch, and a root Nyquist filter calculation processing is executed. A demodulation process of detecting a symbol identification point from the data and extracting digital information of each channel using the data of the detected symbol identification point is executed.

The calculation result of the root Nyquist filter calculation processing section 725 is output to an automatic frequency control (AFC) / bit synchronization section (BTR) 1004, and the automatic frequency control / bit synchronization section 1004 generates a bit synchronization signal. It is output to the synchronization control unit 1005.

The virtual switch 1006 schematically shows that the quadrature detection, root Nyquist filter operation and demodulation of the signal of each channel are executed in a time-division manner. 1005
This is performed based on the synchronization signal output from. The synchronization signal of the synchronization control unit 1005 is output to the sampling clock generation unit 1002, and the sampling clock generation unit 1002 generates a sampling clock synchronized with the synchronization signal.

According to the second embodiment, quadrature detection processing, root Nyquist filter processing, demodulation processing for extracting digital data before modulation, and the like for signals of a plurality of channels are realized by firmware of a digital signal processor. There is no need to provide an AD converter and a quadrature detector for each channel, and the hardware configuration can be further simplified as compared with the first embodiment.

Next, FIG. 11 is a block diagram for explaining the function of the receiving circuit according to the third embodiment of the present invention. In the third embodiment, multirate communication can be performed by using an arbitrary number of channels among a plurality of channels for one communication. In multi-rate communication, the communication speed can be adjusted adaptively during reception.

The two-channel signals received by the receiving unit 1101 of FIG. 11 are detected and demodulated by a demodulation unit 1102 comprising a digital signal processor or the like.
03, 1104 is performed.

Transmission rate control / adaptive processing section 1105 detects a communication rate notified from the base station or a communication rate that can be synchronized with a received signal, and demodulation processing section 110.
3, 1104, the filter band of the root Nyquist filter operation or the demodulation bit rate is set.

That is, the communication speed specified by the base station or the bit rate of the signal transmitted from the base station can be detected, and the communication speed can be adaptively adjusted at the time of reception.

FIG. 12 is a diagram showing an example of the configuration of the receiving circuit according to the third embodiment. In FIG. 12, a demodulation unit 1201 includes a root Nyquist filter
5, in addition to the demodulation processing unit 726, a digital filter band change control unit 1202 that changes the filter band of the root Nyquist filter operation unit 725 according to the transmission rate, and a demodulation rate change unit 1203 that changes the demodulation rate of the demodulation processing unit 726 And

Digital filter band change controller 1202
And the demodulation rate changing unit 1203
The band of the root Nyquist filter unit 725 and the demodulation unit 726 according to the control signal input from the
Change the demodulation rate of

The transmission rate control unit 1204 includes an input unit 1
A transmission rate manually set by the user of the mobile station or a control signal sent from the base station is input from 205, and the transmission rate control unit 1204 changes the band and demodulation rate of the Nyquist filter based on those input signals. Outputs control signal.

Now, the frequency of the carrier 1 of the received signal is 40
0.000 MHz, carrier 2 frequency 400.02
5 MHz, the second intermediate frequency of carrier 1 is 455 KH
z, the second intermediate frequency of carrier 2 is 480.000 KH
z. As shown in FIG. 13A, the bandwidth of the second intermediate frequency filter 711 is
the second intermediate frequency signal of z and 480.000K of carrier 2
The bandwidth is set such that the second intermediate frequency signal of Hz falls within the pass band.

When the transmission rate is low, the characteristic of the root Nyquist filter of carrier 1 is as shown in FIG.
As shown in (B), the band may be narrow according to the characteristics of the baseband signal of the carrier 1. However, when the transmission rate is high, the band of the baseband signal is widened, so it is necessary to match the band.

Therefore, in the third embodiment, the filter band of the root Nyquist filter operation is changed according to the transmission rate of the signal, and the root Nyquist filter operation having filter characteristics suitable for the transmission rate is performed. I made it. As a result, even when the transmission rate is made variable, a root Nyquist filter operation suitable for the changed band can be executed, so that data can be correctly demodulated and a function of a channel selection filter that blocks adjacent unnecessary waves is provided. Become.

FIG. 14 is a diagram showing a sequence when the communication speed is changed, and FIG. 15 is a diagram showing a frame format used for communication between the base station and the mobile station when the communication speed is changed. .

Mobile station A and mobile station B have a narrow band, that is, 8k
After communication at a low communication rate of bps, when a termination signal is transmitted from the mobile station A to the relay station (base station), the channel used so far is released.

Next, when the mobile station A requests communication at a wide band, that is, at a high communication speed, the relay station monitors the communication traffic in the area of the own station, so that the relay station monitors the traffic in the wide band (for example, 32 kbps). If communication is possible, communication permission is given to the mobile station A and the partner station, and the channel to be used and the communication speed are notified.

When a broadband communication of 32 kbps is instructed by the relay station, demodulation sections 1201 of mobile station A and mobile station B
Changes the filter band in the root Nyquist filter calculation to one corresponding to the communication speed. Further, the bit rate of the demodulation processing unit 726 is changed to a value corresponding to the communication speed.

The change of the communication speed from the relay station to the mobile station is instructed based on the frame format of the communication channel shown in FIG. A frame is a minimum communication unit of a channel, and the channel is composed of a communication channel having a different frame format and a synchronization burst. The communication channel includes a preamble (PR), a channel (BCCH) for transmitting user information, a radio information channel (RICH) for transmitting channel information such as an operation mode and a communication mode, and a synchronization word (RICH). SW), BCCH, guard time (G) for guarding the signal content only during the collision time of the received frame, and the like. The communication speed is specified by the radio information channel RICH in the frame format, and the frame is transmitted from the base station to the mobile station to instruct the change of the communication speed.

Next, FIG. 16 is a flowchart of the processing of the demodulation unit 1102 when the communication speed is adaptively adjusted at the time of reception. First, receive at the slowest 8 kbps (Fig. 1
6, S11), it is determined whether there is an RSSI level (S12). If the RSSI level is detected, it is determined whether synchronization has been achieved (S13). If the synchronization is established (S13, OK), the flow returns to step S11 to 8 kbp
Continue receiving at s.

If the synchronization is not achieved at 8 kbps (S13, NO), the process proceeds to step S14 to 16 kbps.
To receive. Then, it is determined whether or not synchronization has been achieved at 16 kbps (S15). If synchronization has been achieved, the process returns to step S14 to continue reception at 16 kbps.

If synchronization is not achieved at 16 kbps (S15, NO), the process proceeds to step S16, where 32 kbps is set.
s performs reception. Then, it is determined whether or not synchronization has been achieved at 32 kbps. If synchronization has been achieved at 32 kbps, the process returns to step S16 to continue reception at 32 kbps.

According to the third embodiment, a plurality of channels can be used independently, or data can be transmitted by simultaneously using an arbitrary number of the plurality of channels in one communication. Therefore, the communication speed between the mobile stations and between the base station and the mobile station can be set to the optimum communication speed according to the communication traffic. This allows you to use available frequencies,
The wireless resources of the wireless communication system can be used effectively.

FIG. 17 is a diagram showing a main part of a receiving circuit according to a fourth embodiment of the present invention. In the fourth embodiment, when the channel interval is wider than the pass band width of the intermediate frequency filter, the channel interval on the intermediate frequency filter is compressed by using a local oscillator corresponding to the frequency of each channel. It is.

The frequency Fb of the channel b received by the receiving circuit shown in FIG. 17 is, for example, 380 MHz, the frequency Fa of the channel a is, for example, 410 MHz, and the channel interval between them is 30 MHz. On the other hand, the intermediate frequency filter 707 has a center frequency of 10 MHz and a pass bandwidth of 50 MHz.
Since the frequency is kHz, the intermediate frequency signal for two channels cannot be passed through the intermediate frequency filter 707 as it is. Therefore, two local oscillators 1701 and 1702 having oscillation frequencies of 390.025 MHz and 400 MHz are provided.
By mixing the local oscillation signal of each channel 702, the frequency of each channel and the local oscillation frequency 390.025 MH
The signal is converted into an intermediate frequency signal having a frequency different from that of z and 400 MHz.

As described above, the center frequency of the intermediate frequency filter 707 is 10 MHz, and the pass bandwidth Bw is 50 kHz.
Therefore, the 10.000 MHz intermediate frequency signal Fa1 of the channel a and the 10.025 MHz intermediate frequency signal Fb1 of the channel b can pass through the intermediate frequency filter 707.

FIG. 18 is a diagram showing an example of the configuration of a receiving circuit according to the fourth embodiment. FIG. 18 also shows a filter band changing unit 1202, a demodulation rate changing unit 1203, and a transmission rate control unit 1204 according to the third embodiment.

In FIG. 18, local oscillators 1801, 1
Reference numeral 802 has the same function as the local oscillators 1701 and 1702 in FIG. 17, and the respective local oscillation frequencies are set so that the intermediate frequency signal of the corresponding channel enters the pass band of the intermediate frequency filter 707. . Mixer 70
5 mixes the local oscillation signals generated by the local oscillators 1801 and 1802 with the reception signal, and outputs the mixed signal to the intermediate frequency filter 707.

Thus, even when the channel interval is larger than the pass band width of the intermediate frequency filter 707, the intermediate frequency signals of those channels are converted to the same intermediate frequency filter 707.
07, and by demodulating signals of a plurality of channels by compressing the channel interval, digital demodulation of the demodulation unit 1201 can be performed.

FIGS. 19A and 19B are diagrams showing the frequencies of the received signal and the input signal of the intermediate frequency filter 707 in the receiving circuit of FIG. Now, as shown in FIG. 19A, the receiver of the mobile station has a frequency of 380.000 MHz and 41 MHz.
The signal of two channels of 0.000 MHz is received, and the center frequency of the intermediate frequency filter 707 is set to 10.125 MHz.
Assuming that z and the pass bandwidth are 50 kHz, the oscillation frequencies of the local oscillators 1801 and 1802 are
If set to 390.025 MHz and 400.000 MHz, the received signals will be 10.025 MHz and 10.000 MHz, respectively.
It is converted to an intermediate frequency signal of 000 MHz. Since the frequency difference between the two is 25 kHz, the two intermediate frequency signals fall within the pass band of the intermediate frequency filter as shown in FIG.

According to the fifth embodiment, when communication is performed using a plurality of channels simultaneously, even if the channel interval is wide, the frequency interval can be narrowed when converted to an intermediate frequency signal. Digital operation of the Nyquist filter of the channel signal can be performed by an arithmetic element such as a digital signal processor.

Next, the same data is transmitted on a plurality of channels, and signals on those channels are selected or combined on the receiving side so that more reliable communication quality can be ensured. An embodiment will be described.

FIG. 20 is a diagram showing a basic configuration of a receiving circuit according to a fifth embodiment of the present invention, which detects signal power of each channel and selects / combines channels. Now, it is assumed that the same data is transmitted from the base station on two channels of frequencies fa and fb. The receiving unit 2001 performs the first
An intermediate filter 707, an amplifier 708, a mixer 709,
It comprises a demodulation unit composed of a digital signal processor and the like, and demodulates the received signal into baseband signals of the respective channels a and b. Power detection circuits 2002 and 2003 detect the power of the baseband signals of channel a and channel b, respectively, and output the detection result and the respective baseband signals to selection / combination circuit 2004.

Selection / synthesis circuit 2004 selects a baseband signal of a channel having a large reception power according to the detection result of two-channel power detection circuit 2002.2003, or synthesizes a baseband signal of a channel whose reception power is equal to or more than a predetermined value. I do.

FIG. 21 is a diagram showing an example of the configuration of the receiving circuit according to the fifth embodiment. In the example of FIG.
The same information is transmitted at two types of frequencies, 000 MHz and 400.025 MHz.

The receiving circuit of FIG. 21 is substantially the same as the circuit configuration of the third embodiment of FIG. 12, except that the quality of the signal of each channel demodulated by demodulation section 726 is detected. A switching unit 2101 for selecting or combining received signals based on the result is provided.

Next, referring to FIGS. 22 and 23, FIG.
An example of a specific configuration of the switching unit 2101 will be described. FIG.
FIG. 2 is a diagram showing a configuration of an equal gain combining diversity circuit. In FIG. 23, assuming that one of the two channels is a system 1 and the other is a system 2, the I-channel signal and the Q-channel signal of each channel demodulated by the demodulation unit 726 are output from the amplitude / phase detection units 2201 and 2202. And a phase are detected, and a phase difference between the two is detected by a phase detector 2203. Then, the phase detector 2203 controls the phase shifter 2 so that the phase of the signal of the second system matches the signal phase of the first system.
The amount of phase shift of 204 is controlled. After that, the signals of the two channels are combined in the combining unit 2205, and the digital data before modulation is extracted in the extracting unit 2206.

FIG. 23 is a diagram showing a configuration of the maximum ratio combining diversity circuit. 1 channel, 2 channel I channel signal, Q
The channel signals are output from the amplitude / phase detector 2301,
At 2302, the signal amplitude and phase are detected. Then, a phase difference between the two is detected by the phase detector 2303, and the phase detector 2303 controls the phase shift amount of the phase shifter 2304 so that the signal phase of the second system matches the signal phase of the first system.

The amplitude controllers 2305 and 2306 determine the amplitude
Variable gain amplifiers 2307 and 230 based on the amplitude values detected by phase detection sections 2301 and 2302, respectively.
8 is controlled. For example, the amplitude / phase detection unit 23
When the amplitude value of the signal detected at 01 is larger than the upper limit value, the gain of the variable gain amplifier 2307 is reduced to correct the signal level to an appropriate value. When the received signal level is so low that it cannot be distinguished from noise, the signal quality is degraded by adding the signal. Therefore, when the amplitude value is equal to or lower than the lower limit value, the gain of the variable gain amplifier 2307 is reduced and the signal is synthesized. 2309 so as not to be output.

According to the maximum ratio combining diversity circuit, the same information is transmitted using a plurality of channels, and the reception side synthesizes a signal whose reception signal amplitude is within an appropriate range. However, more reliable communication quality can be secured.

According to the fifth embodiment, the same information is transmitted using a plurality of channels, the signal quality is detected based on the amplitude, power, etc. of the signals of the plurality of channels. By selecting or synthesizing, highly reliable communication can be performed. Also, since a diversity effect can be obtained without providing a plurality of wireless signal receiving units and demodulating units, the size of a digital wireless device capable of performing high-quality communication can be reduced.

Next, FIG. 24 is a diagram showing a basic configuration of a receiving circuit according to a sixth embodiment of the present invention. This sixth embodiment also realizes high-quality communication by transmitting the same information from a base station through a plurality of channels and selecting or combining signals with good signal quality on the receiving side. Therefore, in the sixth embodiment, a narrow-band filter corresponding to each carrier is provided, the power of the output signal of the narrow-band filter is compared, and a channel of good signal quality is compared based on the comparison result. Signals are selected or combined.

In FIG. 24, the intermediate frequency signals converted by receiving section 2401 are output to power detecting sections 2404 and 2405 through narrow band filters 2402 and 2403 that pass the intermediate frequency signals of the respective channels. Power detection sections 2404 and 2405 detect the signal power of each channel and output the detection result to selection / combination section 2406.

The intermediate frequency signal output from the receiving section 2401 passes through a wide band filter 2407 having a pass band width of the intermediate frequency signals of a plurality of channels, and is demodulated by a demodulating section 2408 comprising a digital signal processor to be selected / combined by a selecting / combining circuit 2406. Is output to

The selecting / synthesizing unit 2406 includes the power detecting unit 24
On the basis of the detection results obtained by the demodulation unit 2408
The signal of the channel with the larger signal power is selected from the signals of the plurality of channels output from the, or the signals of the two channels are combined and output.

FIG. 25 is a diagram showing an example of the receiving circuit according to the sixth embodiment. The receiving circuit of FIG. 25 is basically the same as the receiving circuit of FIG. 7, except that the narrow band intermediate frequency filters 2501 and 2502 and the power comparing section 2503
And a switching unit 2504.

The narrow band intermediate frequency filter 250 shown in FIG.
Reference numerals 1 and 2502 denote narrow-band filters that pass only signals of a specific channel among the second intermediate frequency signals of a plurality of channels output from the mixer 709. FIG.
, Narrow band intermediate frequency filters 2501 and 250
2 has a center frequency of 455,000 KHz, 480.0
00 KHz narrow band filter, and only the second intermediate frequency signal of the corresponding channel is a narrow band intermediate frequency filter 2
501 and 502. Then, the power comparison unit 25
At 03, the signal powers of the two signals are compared. The comparison result of power comparing section 2503 is output to switching section 2504 as switching information, and switching section 2504 selects a signal of a channel having a large received power, or combines both signals and outputs the result as a demodulated signal.

FIG. 26 is a diagram showing an example of a narrow band filter. FIG. 26 shows a filter having a center frequency of 455 kHz and a pass bandwidth of about 20 kHz. By using the narrow-band filters having such characteristics as the narrow-band intermediate frequency filters 2501 and 2502 in FIG. 25, a signal of a specific frequency can be extracted.

In the sixth embodiment, the same information is transmitted on a plurality of channels, the signal power of each channel is compared on the receiving side, and the signal of the channel with the higher power is selected or combined, whereby Even when the reception state of one channel is poor, a signal of another channel is received, and by selecting or combining the signals, highly reliable communication quality can be ensured. Further, in the sixth embodiment, since a diversity effect can be obtained without providing a plurality of antennas and a receiving circuit, there is a great effect on downsizing the receiving device. Further, the purpose of the narrow band filter in this case is to extract power information, and since phase information is not required, it is not necessary to consider the group delay characteristic, so that a small and inexpensive filter can be used.

Next, FIG. 27 is an explanatory diagram of a radio system according to the seventh embodiment of the present invention, and FIG. 28 is a diagram showing a basic configuration of a receiving circuit of a mobile station according to the seventh embodiment. is there.
According to the seventh embodiment, as shown in FIG.
01 and the mobile station are performed by uplink / downlink duplex / half duplex / two-wave simplex system, and the base station 601 returns a signal transmitted from the mobile station of the communication partner. It relates to a system that can transmit.

For example, by setting the first intermediate frequency of the mobile station to half the frequency difference between the downlink radio wave from the base station and the uplink radio wave from the partner mobile station, the downlink radio wave from the base station and the partner mobile station are set. Are arranged in the intermediate frequency band at an interval corresponding to both channel offsets. Then, the mobile station receives and demodulates two signals, a signal transmitted from the partner mobile station and a signal transmitted from the partner mobile station via the base station, and selects a signal having better signal quality. Alternatively, the communication quality between mobile stations can be improved by combining a plurality of signals.

A signal received by antenna 2801 shown in FIG. 28 is selected by radio signal receiving section 2802 by amplification and a filter, and a signal in a certain frequency range is output to mixer 2803. The oscillation frequency of the local oscillator 2804 is set to a value such that the intermediate frequency signal of the downstream radio wave from the base station 601 and the intermediate frequency signal of the upstream radio wave of the partner mobile station 602 fall within the pass band of the intermediate frequency filter 2805 at the subsequent stage. Is set. Thus, the intermediate frequency signal of the downstream radio wave from the base station 601 and the intermediate frequency signal of the upstream radio wave from the partner mobile station 602 can pass through the same intermediate frequency filter 2805.

The signal that has passed through the intermediate frequency filter 2805 is mixed with a local oscillation signal generated by a local oscillator (not shown) in a mixer 2806 at the next stage, converted into a second intermediate frequency signal, and sent to the intermediate frequency filter 2807. Is output.

Signals from the base station and mobile station B that have passed through intermediate frequency filter 2807 are demodulated into baseband signals by demodulation section 2808 and output to selection circuit 2809. The selection circuit 2809 has a detection unit for detecting the signal quality of the baseband signals of a plurality of channels, and based on the detection result of the detection unit, the signal from the partner mobile station 602 returned by the base station 601 and the partner mobile station. A signal having a better signal quality is selected from the signals received directly from 602, or both are combined and output.

The relationship between the frequency of the transmission signal of the base station and the mobile station and the pass band of the intermediate frequency filter is shown in FIG.
This will be described with reference to FIG. For example, the frequency of the downstream radio wave from the base station 601 is 380 MHz, the frequency of the upstream radio wave from the mobile station B of the communication partner is 400.025 MHz, and the center frequency of the intermediate frequency filter 2805 is about 10.0125.
MHz, and the pass bandwidth is about 50 kHz. In that case, the oscillation frequency of the local oscillator 2804 is set to 390 MHz.
, The intermediate frequency signal of the downstream radio wave from the base station 601 is 10.000 MHz, and the intermediate frequency signal of the upstream radio wave from the partner mobile station is 10.025 MHz. Since these two intermediate frequency signals fall within the pass band of the intermediate frequency filter 2805, the intermediate frequency signals can be independently demodulated by digital operation in the demodulation unit 2808 at the subsequent stage.

That is, the opposite mobile station 6 which receives via the base station 601 transmitted on different channels, respectively.
02 and a signal directly received from the partner mobile station 602 are simultaneously received and demodulated, their signal qualities are compared, and a signal having a better signal quality or a signal obtained by combining these signals is obtained. By this, the effect of noise and the like can be removed and the communication quality between mobile stations can be improved.

When the frequency of the downlink radio wave of the base station 601 is different from the frequency of the uplink radio wave of the partner mobile station,
For example, as in the above-described fourth embodiment, two local oscillators are provided, and the mixer 2803 mixes the oscillated signals of the two local oscillators and the received signal, so that the signal passes through the intermediate frequency filter. What is necessary is just to convert it into an intermediate frequency signal of a frequency that falls within the band.

The seventh embodiment is directed to a system in which a signal transmitted from a mobile station can be looped back and transmitted by a base station. Since two signals of the signals to be received can be simultaneously received using a plurality of channels, the quality of those signals can be detected, and information can be extracted from the signal having the better signal quality, so that communication between mobile stations can be performed. Even when the state is bad, errors in the received data can be reduced.

FIG. 30 is a diagram showing a basic configuration of a receiving circuit according to an eighth embodiment of the present invention. In the eighth embodiment, a mobile station has a function of receiving a plurality of channels, detects a received signal level of each channel using a narrow-band filter corresponding to each channel, and responds to the signal level of each channel. To perform optimum gain control.

In FIG. 30, an intermediate frequency signal received by an antenna 3001 and converted by a receiving unit 3002 passes through a wide band filter 3003 that passes intermediate frequency signals of a plurality of channels, and is demodulated by a demodulation unit 3004 including a digital signal processor. And demodulated by the extraction unit 3005
Extracts the original digital data.

The intermediate frequency signal output from receiving section 3002 passes through narrow band filters 3006 and 3007 that pass the intermediate frequency signal of each channel, and the signal power of each channel at power detection sections 3008 and 3009 is reduced. Is detected.

AGC section 3010 includes power detection section 300
The optimum gain control is performed for a plurality of channels by controlling the gain of the amplifier in the receiving unit 3002 in accordance with the received signal power of each channel detected in 8,3009. As a result, it is possible to maintain the linearity of the receiver and reduce mixing due to distortion of carrier waves of a plurality of channels.

Next, FIG. 31 is a diagram showing an example of the configuration of the receiving circuit of the eighth embodiment. The receiving circuit of FIG. 30 is basically the same as the receiving circuit of FIG.
Narrow band filter 3 corresponding to the intermediate frequency signal of each channel
101 and 3102, and an AGC unit 3103 for controlling the gains of the amplifiers 703 and 708.

The narrow band filter 3101.3102 is a filter having a narrow pass band centered on the frequency of the second intermediate frequency signal output from the mixer 709. A
The GC unit 3103 includes narrow band filters 3101 and 3102
And a power detection unit that detects the signal power of each channel output from the power supply unit, and controls the gains of the amplifiers 703 and 708 according to the signal power of each channel detected by the power detection unit.

FIG. 32 shows the narrow band filters 3101 and 31.
FIG. 3 is a diagram showing a relationship between the carrier No. 02 and carriers of channels a and b. Assuming that the frequency of the carrier 1 is 455,000 KHz and the frequency of the carrier 2 is 480.000 KHz, the narrow band filters 3101 and 3102 having a pass bandwidth as shown in FIG. Only one carrier can be taken out. And these narrow band filters 310
By detecting the power of the output signals of 1,3102, the reception levels of carrier 1 and carrier 2 can be accurately detected.

FIG. 33 is a block diagram of the AG
It is a flowchart of C processing. First, the power of carrier 1 and carrier 2 is detected from the intermediate frequency signals of a plurality of channels output from narrow band filters 3101 and 3102 (FIG. 33, S11). Next, it is determined whether the power of the carrier 1 or the carrier 2 is equal to or higher than the saturation level of the amplifier (S12).

If the power of carrier 1 and carrier 2 is less than the saturation level of the amplifier (S12, NO), the process proceeds to step S13 to increase the gain of the amplifier. On the other hand, if the power of the carrier 1 or the carrier 2 is equal to or higher than the saturation level of the amplifier (S12, YES), the process proceeds to step S14 to determine whether the level difference between the two carriers, that is, the detected power difference is smaller than a predetermined value. Determine.

When the detected power of carrier 1 or carrier 2 is equal to or higher than the saturation level of the amplifier and the power difference between the two carriers is smaller than a predetermined value, both carriers can be received even if the gain of the amplifier is reduced. Since it is possible, the process proceeds to step S15, and the gain of the amplifier is reduced.

If the power difference between the two carriers is larger than the predetermined value in step S14 (S14, NO), if the gain of the amplifier is reduced, it becomes impossible to receive a signal having a small reception level. (**
It is determined whether the value is equal to or greater than the value obtained by adding (dB) (S16).

If the detected power is equal to or higher than the value obtained by adding the predetermined value to the saturation level (S16, NO), the reception of the two channels is abandoned, and the process proceeds to step S15 to reduce the gain of the amplifier.

On the other hand, if the detected power is less than the value obtained by adding a predetermined value to the saturation level (S16, NO), the gain of the amplifier is adjusted to prevent a carrier having a low reception level from becoming unreceivable. leave it as it is.

In the above-described eighth embodiment, the power of the received signal is detected. However, the present invention is not limited to this. For example, amplitude, phase, or information obtained by combining them may be detected. .

According to the eighth embodiment, the optimum AGC can be performed for a plurality of carriers.
The linearity of the receiving circuit can be maintained, and mixing due to carrier distortion can be reduced.

Next, FIG. 34 is a system configuration diagram of a ninth embodiment of the present invention. In the ninth embodiment,
The line device controls the communication speed between the base station and the mobile station according to the traffic information of the wireless line.

In FIG. 34, the radio communication system according to the ninth embodiment includes a base station radio apparatus 3401 and a mobile station 3.
402 and a line controller 340 for controlling their communication.
And 3.

FIG. 35 is a diagram showing a sequence of a mobile station, a base station (base radio apparatus) 3401 and a control station (line control apparatus) 3403. When a broadband communication request, that is, a communication request with a high communication speed for simultaneously using a plurality of channels is sent from the mobile station A to the base station 3401, the base station 34
01 informs the control station 3403 that there is a broadband communication request from the mobile station A.

Upon receiving the communication request, control station 3403 determines whether or not the traffic of the entire system is large from the traffic information. If the traffic is large, control station 3403 does not permit base station 3401 to accept the broadband communication request. Notify that there is. Then, the base station 3401 notifies the mobile station A that the broadband communication request cannot be permitted.

Next, when mobile station A sends a narrowband communication request to the base station, base station 3401 sends the narrowband communication request to control station 3403. In this case, since the request is for a narrowband communication, the control station 3403 allocates a narrowband channel to the mobile station A.

When the communication channel is assigned, mobile station A communicates with mobile station B via base station 3401. Then, when there is a call termination request, the control station 3403 sends the request to the base station 34.
01 is notified of the release of the channel.

Also, when a mobile station requests a broadband communication,
At that time, when the communication traffic of the system is small, the control station 3403 notifies the base station 3401 and the mobile station of the plurality of channels to be used and the transmission speed.

If broadband communication using a plurality of channels is permitted, the mobile station uses circuits such as the transmission rate control unit 1204, filter band change unit 1202, and demodulation rate change unit 1203 described in the third embodiment. To perform broadband communication.

According to the ninth embodiment, the base station and the mobile station can realize communication at a high communication speed by allocating a plurality of channels to one communication at the same time and performing broadband communication. At this time, the control station 3403 monitors the traffic of the entire wireless system and determines whether or not the communication can be permitted at the requested communication speed according to the traffic. To set the optimum communication speed.

FIG. 36 is an explanatory diagram of a system capable of simultaneously performing voice communication and data communication in the wireless system according to the ninth embodiment. This wireless system performs communication between a base station 3401 and a mobile station 3402 and performs communication using a two-wave duplex method, a half-duplex method, or a two-wave simplex method using two downlink frequencies. It is.

In the example of FIG. 36, the mobile station 3402 can receive two-channel signals, perform voice communication on one channel, and simultaneously perform data communication such as facsimile on the other channel. If data communication is performed using these two channels simultaneously, data can be transmitted and received at a higher communication speed.

FIG. 37 is a diagram showing a control sequence of a mobile station, a base station and a control station according to the tenth embodiment of the present invention. In the tenth embodiment, as shown in FIG. 38, when mobile station B is out of range of base station 3701 and mobile station A can receive radio waves of both base station 3701 and mobile station B, The mobile station B outside the service area can follow the frequency of the base station 3701. In addition, the tenth
Another example of the embodiment of the present invention is that a plurality of ones are used for a communication channel and the other channels are used for a control channel so that it can simultaneously communicate with another mobile station while receiving frequency information from a base station. Things.

The configuration of the radio system according to the tenth embodiment is the same as that of FIG. 34 described above, and a control station 37 for allocating radio channels to a base station 3701 and a plurality of mobile stations.
02.

[0128] As shown in FIG.
Assuming that the mobile station A is out of the communication range and the mobile station A is in the service area, the mobile station A receives the frequency information of the control channel when the downlink channel of the base station 3701 or one of the plurality of channels is allocated to the control channel. , Base station 3701
Can be followed.

In this case, mobile station B is located outside the area of base station 3701, and it is difficult for the mobile station B to follow the frequency of base station 3701 because the reception level of the signal of base station 3701 is low. Since the mobile station A can communicate with the mobile station B, the mobile station A directly calls the mobile station B to perform communication. At this time, the mobile station A can transmit a signal synchronized with the frequency of the base station 3701 to the mobile station B by simultaneously communicating with the base station 3701 using another channel. Therefore, mobile station B can follow the frequency of base station 3701 by following its own frequency to the frequency of mobile station A.

As a result, it is possible to improve the frequency tracking accuracy of the mobile station B located outside the communication range of the base station 3701 with respect to the base station 3701, and to maintain the frequency accuracy. Quality can be kept high.

Next, a case in which one of the plurality of channels is used as a control channel used for frequency control and the other channel is used as a communication channel will be described with reference to the sequence diagram of FIG.

The control channel is used as a control channel for transmitting information for designating a communication speed, a communication channel with a mobile station, a reference frequency channel, or both. Mobile station A and mobile station B perform frequency control so as to follow the frequency of base station 3701 based on control channel data. At this time, when the mobile station A sends a communication request to the mobile station B to the base station 3701, the communication request is sent to the control station 3702, and the control station 3702 sends the request to the mobile station A.
And a communication channel is allocated to the mobile station B.

The mobile station A and the mobile station B communicate via the base station using the respectively assigned communication channels, and based on the frequency information of the control channel (for example, a clock signal transmitted from the base station). Each base station 3
The quadrature demodulator 713 or a reference frequency for demodulation of digital operation is controlled so as to follow the frequency 701.

By using one of the plurality of channels as a control channel for frequency tracking as described above, the mobile station can simultaneously follow the frequency of the base station while communicating with another mobile station. In such communication, the accuracy of following the frequency of the base station can be improved.

According to the tenth embodiment, when mobile station B is located outside the communication range of base station 3701 and base station 3
Even when the reception level of the signal transmitted from the base station 701 is low and it is difficult to follow the frequency of the base station 3701, the mobile station communicates with another mobile station A located near the own station B within the base station area and the mobile station A By following the frequency of the station A, the base station 3
701 can be followed.

Further, one of the plurality of channels is used as a control channel for receiving frequency information and the like from the base station, and the other channel is used as a communication channel. It is possible to follow the frequency of the station. This makes it possible to solve the problem that it is impossible to receive frequency information from the base station when performing communication between mobile stations using a duplex or semi-duplex method as in the related art, thereby improving the frequency tracking accuracy.

In the tenth embodiment described above, a wireless communication system including a mobile station, a base station 3701, and a control station 3702 has been described. However, the present invention is also applicable to a wireless communication system having no control station 3702. Applicable. One example of the tenth embodiment is that the mobile station B communicates with the mobile station A in the base station area when the mobile station A is in the base station area and the mobile station B is out of the service area. It is only necessary to follow the frequency of the station. In another example, it is only necessary that the frequency can be controlled so that the mobile station can follow the frequency of the reference base station based on the control information of the control channel.

The above embodiment has been described with reference to the case where the present invention is applied to a business radio system. However, the present invention is not limited to this and can be applied to other digital radio systems. In addition, the number of channels simultaneously received is not limited to two channels,
There may be three or more channels.

The configuration of the receiving section and the demodulator of the receiving circuit is not limited to those described in the embodiment, and may be, for example, a demodulator other than the quadrature demodulator.

[0140]

According to the present invention, when signals of a plurality of channels are simultaneously received or transmitted, there is no need to provide an RF receiver and hardware demodulation circuits or modulation circuits for the number of channels. The circuit configuration of the digital wireless device is simplified. Further, since the transmission rate can be varied by using an arbitrary number of channels out of a plurality of channels for one communication, wideband communication can be realized by efficiently using the radio resources of the digital radio communication system. . Also, when receiving a plurality of channels, even if the frequencies of the channels are distant, the signals can be converted into an intermediate frequency signal that falls within the pass band of the intermediate frequency filter. further,
By transmitting the same information to a plurality of channels and demodulating them, a diversity effect can be obtained without providing a plurality of antennas and receiving circuits.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a diagram illustrating a basic configuration of a digital wireless device.

FIG. 3 is a diagram showing a reception signal and an intermediate frequency signal.

FIG. 4 is a diagram showing an intermediate frequency signal and a baseband signal.

FIG. 5 is a diagram illustrating a configuration of an orthogonal transform unit.

FIG. 6 is a diagram illustrating a configuration of a business wireless system according to the first embodiment.

FIG. 7 is a diagram illustrating a configuration of a digital wireless communication circuit according to the first embodiment.

FIG. 8 is an explanatory diagram of a process of a demodulation unit according to the second embodiment.

FIG. 9 is a diagram illustrating a process performed by a modulation unit according to the second embodiment.

FIG. 10 is a diagram illustrating a configuration of a receiving circuit according to a second embodiment.

FIG. 11 is a block diagram illustrating functions of a receiving circuit according to a third embodiment.

FIG. 12 is a diagram illustrating a configuration of a receiving circuit according to a third embodiment.

FIG. 13 is a diagram illustrating a band of a second intermediate frequency filter and characteristics of a root Nyquist filter of the receiving circuit according to the third embodiment.

FIG. 14 is a diagram showing a sequence of a mobile station and a relay station when a communication speed is changed.

FIG. 15 is a diagram showing a frame format of a communication channel.

FIG. 16 is a flowchart in a case where a communication speed is adaptively adjusted.

FIG. 17 is a diagram illustrating a main part of a receiving circuit according to a fourth embodiment;

FIG. 18 is a diagram illustrating a configuration of a receiving circuit according to a fourth embodiment.

FIG. 19 is a diagram illustrating frequencies of a received signal and an input signal of an intermediate frequency filter.

FIG. 20 is a diagram illustrating a basic configuration of a receiving circuit according to a fifth embodiment.

FIG. 21 is a diagram illustrating a configuration of a receiving circuit according to a fifth embodiment.

FIG. 22 is a diagram showing a configuration of an equal gain combining diversity circuit.

FIG. 23 is a diagram illustrating a configuration of a maximum ratio combining diversity circuit.

FIG. 24 is a diagram illustrating a basic configuration of a receiving circuit according to a sixth embodiment.

FIG. 25 is a diagram illustrating a configuration of a receiving circuit according to a sixth embodiment.

FIG. 26 is a diagram illustrating an example of a narrow band filter.

FIG. 27 is an explanatory diagram of a wireless system according to a seventh embodiment.

FIG. 28 is a diagram illustrating a basic configuration of a receiving circuit according to a seventh embodiment.

FIG. 29 is a diagram illustrating the relationship between the frequencies of the transmission signals of the base station and the mobile station and the passband of the intermediate frequency filter.

FIG. 30 is a diagram illustrating a basic configuration of a receiving circuit according to an eighth embodiment.

FIG. 31 is a diagram illustrating a configuration of a receiving circuit according to an eighth embodiment.

FIG. 32 is a diagram illustrating a relationship between a narrowband filter and a carrier.

FIG. 33 is a flowchart of an AGC process.

FIG. 34 is a system configuration diagram of a ninth embodiment.

FIG. 35 is a control sequence diagram of a mobile station, a base station, and a control station according to the ninth embodiment.

FIG. 36 is an explanatory diagram of a system that enables simultaneous communication of voice communication and data communication in the ninth embodiment.

FIG. 37 is a sequence diagram of a mobile station, a base station, and a control station according to the tenth embodiment.

FIG. 38 is a diagram illustrating positions of mobile stations according to the tenth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Receiving part 2 Detection means 3, 4 Calculation means 713 Quadrature demodulator 720 Demodulation part 901 Modulation part 2002, 2003 Power detection part 20004 Selection / combination

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04L 29/08 H04L 13/00 307C 27/00 27/00 Z F term (Reference) 5K004 AA01 BA02 BD00 5K020 AA08 BB06 DD00 EE02 EE03 EE04 EE05 FF04 HH13 5K022 AA07 AA10 AA16 AA24 AA26 AA41 5K034 AA11 DD03 EE03 FF02 FF13 JJ11 MM08 TT02 5K067 AA42 BB04 CC02 DD13 DD34 DD51 EE02 EJ11 H01

Claims (27)

[Claims] A receiving unit that receives a plurality of channels of radio signals divided on a frequency axis; and a plurality of conversion units that convert the plurality of channels of radio signals received by the receiving unit into an intermediate frequency signal or a baseband signal, respectively. And a calculating means for independently demodulating a plurality of intermediate frequency signals or baseband signals converted by the plurality of converting means by digital calculation processing. 2. A receiving section for receiving radio signals of a plurality of channels divided on a frequency axis, and converting the radio signals of the plurality of channels received by the receiving section into an intermediate frequency signal or a baseband signal, respectively. A digital radio apparatus comprising: arithmetic means for performing digital arithmetic processing for independently demodulating a plurality of intermediate frequency signals or baseband signals. 3. The communication means according to claim 1, wherein said arithmetic means includes communication speed changing means for changing a communication speed by using an arbitrary number of said plurality of channels for one communication. 3. The digital wireless device according to 2. 4. The digital radio apparatus according to claim 1, wherein said arithmetic means comprises a digital signal processor. 5. When the digital filter performs a filtering process on the signals of a plurality of channels after the detection, the arithmetic means includes a pass band characteristic or an attenuation characteristic of the filter according to the communication speed changed by the communication speed changing device. 4. The digital wireless device according to claim 3, wherein: 6. The digital radio apparatus according to claim 3, wherein said communication speed changing means switches the communication speed based on a request from a user or a control signal sent from outside. 7. The method according to claim 1, wherein said calculating means detects a communication speed of a signal being received, and demodulates, detects, and demodulates signals of a plurality of channels based on the detected communication speed. 3. The digital wireless device according to 2. 8. The receiving section, when converting the radio signals of a plurality of channels divided on the frequency axis into intermediate frequency signals, the intermediate frequency signals of the plurality of channels fall within the pass band of the same intermediate frequency filter. 3. The digital radio apparatus according to claim 1, further comprising a plurality of local oscillation units having oscillation frequencies corresponding to the frequencies of the respective channels. 9. When the same data is transmitted using a plurality of channels, signal quality detecting means for detecting the signal quality of each channel, and based on the detection result of said signal quality detecting means, 3. The digital radio apparatus according to claim 1, further comprising a selection / synthesis unit for selecting / synthesizing a signal. 10. The digital radio apparatus according to claim 9, wherein said signal quality detecting means detects signal power of a plurality of channels. 11. When the same data is transmitted using a plurality of channels, a plurality of narrow band filters corresponding to the frequencies of the respective channels, and signals of the respective channels passing through the plurality of narrow band filters are provided. 3. A signal quality detecting means for detecting signal quality, and a selecting / synthesizing means for selecting / synthesizing the signals of the plurality of channels based on a detection result of the signal quality detecting means. Digital wireless device. 12. A digital radio apparatus used in a radio communication system in which a signal from a communication partner mobile station is transmitted back at a base station, wherein a signal from the communication partner mobile station is transmitted on one of a plurality of channels. Signal quality detection means for detecting the signal quality of the signal of each channel, when receiving a signal from a partner mobile station looped back by the base station on another channel, detection of the signal quality detection means 2. A selecting / synthesizing means for selecting / synthesizing a signal from a partner mobile station and a signal looped back by a base station based on the result.
Or the digital wireless device according to 2. 13. A narrow band filter corresponding to each frequency of said plurality of channels, detecting means for detecting a signal level of each channel passing through said narrow band filter, and based on a detection result of said detecting means. 3. The digital radio apparatus according to claim 1, further comprising: gain control means for controlling a gain of an amplifier of said receiving section. 14. The digital radio apparatus according to claim 1, wherein said arithmetic means performs bit synchronization or frequency synchronization for signals of a plurality of channels. 15. A radio communication system comprising a mobile station, a base station, and a channel control device for allocating communication channels, wherein the mobile station independently receives radio signals of a plurality of channels by digital arithmetic processing. The line control device detects traffic of the system, and when there is a request for broadband communication, when there is a broadband communication request, the line control device selects one of the plurality of channels according to the traffic detected by the traffic detection unit. Channel allocating means for allocating an arbitrary number of channels to one communication. 16. A digital radio communication system comprising a base station and a mobile station, comprising: a receiving unit for receiving a plurality of channels of radio signals divided on a frequency axis; A plurality of conversion means for converting the radio signals into intermediate frequency signals or baseband signals, respectively; and an arithmetic means for independently demodulating the plurality of intermediate frequency signals or baseband signals converted by the plurality of conversion means by digital arithmetic processing. A digital wireless communication system, comprising: 17. A digital radio communication system comprising a base station and a mobile station, comprising: a receiving unit for receiving radio signals of a plurality of channels divided on a frequency axis; A digital wireless communication system comprising: arithmetic means for independently detecting and demodulating a wireless signal by digital arithmetic processing. 18. A digital radio communication system in which a signal from a communication partner mobile station is transmitted back at a base station, wherein a signal from the communication partner mobile station is used in one of a plurality of channels and another channel is used. When simultaneously receiving signals from the partner mobile station turned back at the base station, signal quality detection means for detecting the signal quality of each channel, from the partner mobile station based on the detection result of the signal quality detection means 2. A selecting / synthesizing means for selecting / synthesizing a signal returned by the base station and a signal returned by the base station.
18. The digital wireless communication system according to 6 or 17. 19. A receiver for receiving a radio signal, comprising: an intermediate frequency signal of a channel used for transmission from the base station;
18. An intermediate frequency conversion unit for converting an intermediate frequency signal of a channel used for transmission from a partner station into a band of the same intermediate frequency filter of the receiving unit. 19. A digital wireless communication system according to claim 18. 20. A digital radio communication system comprising a base station and a mobile station, wherein the first mobile station is located within the base station area and the second mobile station is located outside the base station area. Mobile stations communicate with the base station on one of a plurality of channels, communicate with the second mobile station on another channel, and wherein the second mobile station is transmitted from the first mobile station. 18. The digital wireless communication system according to claim 16, wherein the digital radio communication system follows the frequency of the base station by following the frequency. 21. The digital radio communication system according to claim 16, wherein one of the plurality of channels is used as a control channel for receiving frequency information from a base station, and the other channel is used as a communication channel. 22. An arithmetic unit for independently modulating a plurality of pieces of information to be transmitted into digital signals of a plurality of channels by digital arithmetic processing, and a D / D converter for converting the digital signals of the plurality of channels modulated by the arithmetic unit into analog signals. A digital wireless transmission device, comprising: an A conversion unit; and a transmission unit that converts a plurality of channels of analog signals converted by the D / A conversion unit into a wireless signal and transmits the wireless signal. 23. Receiving radio signals of a plurality of channels divided on the frequency axis, converting the received radio signals of the plurality of channels into intermediate frequency signals or baseband signals, respectively, and converting the plurality of intermediate frequency signals. Alternatively, a digital wireless communication method, wherein a baseband signal is demodulated independently by digital arithmetic processing. 24. A digital communication method comprising: receiving radio signals of a plurality of channels divided on a frequency axis; and independently detecting and demodulating the received signals of the plurality of channels by digital arithmetic processing. 25. The digital wireless communication method according to claim 23, wherein the communication speed is changed by using an arbitrary number of channels among a plurality of channels for one communication. 26. When the same data is transmitted using a plurality of channels, detecting the signal quality of each channel and selecting or combining the signals of the plurality of channels based on the detected signal quality. The digital wireless communication method according to claim 23 or 24, wherein: 27. Independently modulating a plurality of information to be transmitted into digital signals of a plurality of channels by digital arithmetic processing, converting the modulated digital signals of the plurality of channels into analog signals, and converting the analog signals of the plurality of channels into radio signals. A digital wireless communication method, wherein the digital wireless communication method is transmitted.