JPH06125283A - Radio communicaiton system - Google Patents

Abstract

PURPOSE:To provide communication with the same transmission quality as that of a reproduction relay system by compensating added adjacent channel passing interference comprehensively by a reproduction radio station provided with a demodulator and a wave equalizer in a hybrid relay system in which a non-reproduction repeater station is provided between a transmission radio station and a reproduction radio station. CONSTITUTION:Frequency converters 12-20 which select all the output signals of a heterodyne upward or downward for plural transmission/reception local signals used in a frequency conversion function, a reference frequency oscillator 1, and phase synchronous oscillators 9-11 which generate the plural transmission/ reception local signals used in frequency conversion based on the output signal of the oscillator 1 and synchronize the transmission/reception local signals of all the systems in the non-reproduction repeater station 145 are provided in the non-reproduction repeater station 145, and a noise compensating means which compensates the addition of an interference noise generated at the non- reproduction repeater station 145 comprehensively by the wave equalizers 141-143 setting the adjacent channel passing interference so as to be assumed as multipass interference is provided in the reproduction radio station 146.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication system, and in particular, an additive addition of interference noise generated in a non-regenerative repeater station is collectively compensated by a regenerative wireless station having a demodulator and a waveform equalizer to obtain good transmission quality. The present invention relates to a transmission / reception frequency conversion method for a non-regenerative relay station in a communication system that maintains the same.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram showing a configuration example of a conventional regenerative digital radio relay system. It should be noted that the figure shows the case of one relay and two hops, and is an example of three systems. Further, the figure shows an example of a multi-carrier system having 3 carriers per system.

First, in the transmitting radio station 489, modulators 401, 402, 403, 404, 405, 406, 4 are provided.
The modulated signals generated by 07, 408, and 409 are frequency-converted into a predetermined radio frequency band by the transmission devices 410, 411, and 412, and then multiplexed by the multiplexing device 413 in the radio frequency band, and then transmitted by the transmission antenna 414. It is transmitted to the regeneration relay station 490 by using.

In the reproduction relay station 490, the transmitting radio station 489
The modulated signal sent from the receiver is received using the receiving antennas 415 and 416, demultiplexed into each system by the demultiplexer 417, and frequency converted into an intermediate frequency band using the receivers 418, 419, and 420. The modulated signals frequency-converted to the intermediate frequency band are diversity combining devices 421, 422, 4
23, the automatic gain control circuit 424,
It is amplified to a predetermined level by 425, 426, and each of the demodulation devices 427, 428, 429, 430, 43.
1, 432, 433, 434, 435 reproduced in the signal transmitted. Each reproduced signal includes a waveform distortion generated in the propagation path, and the waveform distortion is the waveform equalizer 43.
6,437,438,439,440,441,44
2,443,444 are used for compensation.

Waveform equalizers 436, 437, 438, 43
The signals compensated by 9, 440, 441, 442, 443, 444 are the modulators 445, 446, 447, 44.
Input to 8,449,450,451,452,453. Modulators 445, 446, 447, 448, 44
The modulated signals generated by 9, 450, 451, 452, 453 are frequency-converted into a predetermined radio frequency band by the transmission devices 454, 455, 456, combined by the multiplexing device 457 in the radio frequency band, and then transmitted. It is transmitted to the reproduction wireless station 491 using the antenna 458.

In the reproduction wireless station 491, the reproduction relay station 490
The modulated signal sent from the receiver is received using the receiving antennas 459 and 460, demultiplexed into each system by the demultiplexing device 461, and frequency converted into an intermediate frequency band using the receiving devices 462, 463 and 464. The modulated signals frequency-converted to the intermediate frequency band are diversity combining devices 465, 466, 4
After being combined in 67, the automatic gain control circuit 468,
Amplified to a predetermined level by 469 and 470, and demodulated devices 471, 472, 473, 474 and 47 respectively.
5, 476, 477, 478, 479 reproduced in the signal transmitted. The reproduced signal contains the waveform distortion generated in the propagation path, and the waveform distortion is caused by the waveform equalizer 480,
481,482,483,484,485,486,4
87,488 is used to compensate.

FIG. 5 is a diagram showing the frequency arrangement of each part in the conventional example of FIG. As shown in the same figure, in the frequency conversion from the intermediate frequency band to the radio frequency band or from the radio frequency band to the intermediate frequency band, the output signals (1), (1), (4) of the transmitters 410, 411, 412 of the transmitting radio station 489 of FIG. 2), (3)
And receivers 418, 419, 420 of the replay relay station 490
Then, the output signal of the lower heterodyne, which is a high frequency component, is selected, and the transmission devices 454, 45 of the regenerative repeater station 490 are selected.
5, 456 output signals (4), (5), (6) and the reproduction radio station 491.
In the receiving devices 462, 463, and 464, the output signal of the upper heterodyne, which is a low frequency component, is selected. Therefore, the frequency arrangement of each carrier in each system in the transmission output of the transmitting radio station 489 and the frequency arrangement of each carrier in the intermediate frequency band in each system can be understood from the arrangement of the intermediate frequency band signals shown in FIG. However, the transmission output of the reproduction radio station 490 is different as can be seen from the arrangement of radio frequency band transmission signals shown in FIG.

Next, the generation of interference noise will be described with reference to FIGS. 6 and 7. The interference noise described in the present invention is adjacent channel passing interference. Adjacent channel passing interference in the Sys.2 system occurs as follows.

In FIG. 6, receiving antennas 601 and 602 are provided.
The modulated signal received in 1 is received by the receiving devices 604, 605, 606 for each system via the demultiplexing device 603.
The modulation signals frequency-converted to the intermediate frequency band in the receiving devices 604, 605, 606 are the diversity combining device 6
07, 608 and 609. When the modulated signals are demultiplexed and combined in the automatic gain control circuits 610, 611, 612, the band-pass filters 61, 62, 63, 64, 65, 66, 67, 68, 6 for demultiplexing are performed.
9 is a wide band ((1), (2), (3), (4), (5),
(Refer to (6), (7), (8), (9)), and even a part of its own modulation signal (unnecessary for adjacent modulation signals, hereinafter referred to as interference signal) is adjacent when the modulation signal is demultiplexed. Input to the signal transmission system,
This becomes the desired signal again at the time of multiplexing and is multiplexed with the original desired signal (see (10), (11), and (12) in FIG. 7). This is adjacent channel passing interference (a to i in FIG. 7).

Automatic gain control circuits 610, 611, 612
The modulated signals, of which the fluctuation of the reception level due to the propagation path is corrected by, are frequency-converted into the radio frequency band by the transmitters 613, 614, 615, and are multiplexed in the radio frequency band by the multiplexer 616. At this time, each system is
In the frequency allocation shown in (13), the desired signal that has passed through the adjacent system in the adjacent carrier between the systems is not interfered with the original desired signal (g, c in (13) of FIG. 7).
Adjacent channel passing interference signal) occurs. The reason why the interference signal is generated is that the output signals of the upper heterodyne and the lower heterodyne are used for the frequency of the transmission / reception local signal in the frequency conversion function.

On the other hand, since the interference signal multiplexed with the original desired signal is coherent with B, b leaking into the B channel in Sys.1 of the frequency arrangement shown in (13) of FIG. Since it becomes a multipath interference inside, it can be compensated by the waveform equalizer provided in the reproducing radio station.

[0012]

However, as described above, the interference signal that is not multiplexed with the original desired signal (see FIG. 7).
The g, c adjacent channel passing interference signal in (13) cannot be compensated by the waveform equalizer, and there is a problem that the transmission quality deteriorates.

The present invention has been made to solve these problems, and has a configuration in which the output signal of the upper heterodyne or the lower heterodyne is always selected and output in the transmission / reception frequency conversion of each non-regenerative relay station. It is possible to regard adjacent channel passing interference as multipath interference by generating and synchronizing the transmission / reception local signal of each non-regenerative relay station by multiplying, and adding equalized adjacent channel passing interference to the demodulator and waveform equalization. It is an object of the present invention to provide a communication equivalent to the transmission quality of the regenerative repeater system by collectively compensating at a regenerative radio station having a receiver.

[0014]

SUMMARY OF THE INVENTION The present invention is directed to a transmitting radio station equipped with a modulator, a reproducing radio station having a demodulator and a waveform equalizer corresponding to the modulator, a frequency conversion function and required transmission. In a hybrid relay system having at least one non-regenerative relay station provided between a transmitting wireless station and a regenerative wireless station, which has a regenerative relay device having a function of amplifying to a level, in the non-regenerative relay station, a frequency With respect to a plurality of transmission / reception local signals used for the conversion function, frequency generating means for selecting the output signal of the upper heterodyne or the lower heterodyne to generate a frequency, a reference frequency oscillator, and an output signal of this reference frequency oscillator To generate multiple transmit / receive local signals to be used for frequency conversion, and synchronize the transmit / receive local signals of all systems in the non-regenerative repeater station. The transmission / reception local signal generation / synchronization means is provided, and the noise compensation means for collectively compensating the addition of the interference noise generated in the non-regeneration relay station by the waveform equalizer is provided in the reproduction radio station. is there.

[0015]

According to the present invention having the above-mentioned structure, by always selecting the output signal of the upper heterodyne or the lower heterodyne in the transmission / reception frequency conversion in each non-regenerative relay station, the adjacent channel passage generated in the non-regenerative relay station is passed. The interference can be treated as a part of the self-modulation signal, and in addition, by synchronizing the transmission / reception local signal used for frequency conversion, the interference becomes waveform distortion.

Therefore, the present invention can solve the above-mentioned problems, and the added adjacent channel passing interference is collectively compensated by a regenerative radio station having a demodulator and a waveform equalizer, and has a transmission quality equivalent to that of the regenerative repeater system. Can provide communication.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. Note that the relay system in the figure shows an example in which a transmission wireless station, a non-regenerative relay station, and a regenerative wireless station are configured. Hereinafter, a case where there is one non-regenerative relay station (two hops) will be described.

First, the transmitting radio station 144 uses the modulator 10
The modulated signals generated by 1, 102, and 103 are frequency-converted into radio frequency bands through transmitting devices 104, 105, and 106, and then combined by a combining device 107 to use non-regenerative relay station 145 using transmitting antenna 108. Sent to.

The receiving antenna 10 at the non-regenerative repeater station 145
The modulated signal received by using 9, 110 is the demultiplexer 11
After being demultiplexed into each system at 1, the signals are input to the receiving devices 112, 113, 114 for each system. In the receiving device 112, the output signal of the reference frequency oscillator 1 and the output signal of the frequency divider 5 that divides the required local signal by n (n = 1, 2 ...) Are phase-compared, and the phase comparator 2 outputs After passing through the low-pass filter 3 that removes high-frequency components of the output, the voltage-controlled oscillator 4 is controlled to obtain the required local signal in phase with the reference frequency oscillator 1. Receiver 11
Similarly, 3 and 114 are required local signals which are phase-synchronized with the signal of the reference frequency oscillator 1 by the phase-locking circuits 7 and 8 which are similarly composed of the frequency divider 5, the phase comparator 2, the low-pass filter 3 and the voltage-controlled oscillator 4. To get Each receiving device 112,
The modulated signals input to 113, 114 are the local signals generated as described above and the frequency converters 12, 13, 1
The frequency is converted to an intermediate frequency band via 4, 15, 16, and 17. The frequency-converted modulated signals are combined in diversity combining devices 115, 116 and 117. The fluctuation of the reception level due to the propagation path causes the automatic gain control circuit 11
It is corrected by 8, 119 and 120, and is input to the transmission devices 121, 122 and 123 at a predetermined level. Transmitter 12
1, 122 and 123, the receiving devices 112, 113 and 11
As in the case of 4, the required local signal phase-locked with the reference frequency oscillator 1 is generated in the phase-locked oscillators 9, 10 and 11, and the modulation signals input to the transmitters 121, 122 and 123 are generated as described above. The frequency is converted into a radio frequency band through the local signal and the frequency converters 18, 19 and 20. The frequency-converted modulated signal is amplified to a predetermined level by the transmission amplifiers 21, 22, and 23. The modulated signals output from the transmission devices 121, 122, 123 are multiplexed by the multiplexing device 124 and transmitted to the reproduction wireless station 146 having the demodulation device and the waveform equalizer using the transmission antenna 125.

At the reproducing radio station 146, the receiving antenna 126,
The modulated signal received using 127 is demultiplexed into each system by the demultiplexing device 128, and the output signal thereof is received by the receiving device 1.
Input to 29, 130, 131. Receiver 129,1
The modulated signals frequency-converted to a predetermined intermediate frequency band by 30, 131 are diversity combining devices 132, 133, 1
Automatic gain control circuits 135 and 13 after being synthesized by
Demodulation device 138,1 for each modulated signal via
Input to 39 and 140. Demodulators 138, 139, 1
The adjacent channel passing interference included in the modulated signal frequency-converted into the baseband signal by 40 is the waveform equalizer 14
1, 142, 143 are compensated.

FIG. 2 is a diagram showing a frequency arrangement in the non-regenerative relay station 145 of FIG. Non-regenerative relay station 14 of FIG.
For each of the modulated signals A, B, and C received at 5, the receivers 112, 113, 114 and the transmitter 12 of FIG.
1,122,123 frequency converters 12, 13, 14,
The output signals of 15, 16, 17, 18, 19, and 20 may be selected from the upper heterodyne output signal or the lower heterodyne output signal, but both are adjacent in the radio frequency band transmission signal. The channel passing interference is combined with the original desired signal. Taking the case of selecting the output signal of the lower heterodyne as an example, adjacent channel passing interference (A ′, B ′, C) that occurs in each intermediate frequency band
′) Is multiplexed with the original desired signal in the radio frequency band transmission signal. Since the transmission / reception local signals are synchronized between the systems, the adjacent channel passing interference can be considered as multipath interference in the device. Therefore, the adjacent channel passing interference becomes waveform distortion, and can be completely compensated by the waveform equalizer provided in the non-regenerative repeater station 145. The same compensation can be performed when the output signal of the upper heterodyne is selected.

FIG. 3 shows an application example of the present invention, showing a non-regenerative multi-relay system as a three-non-regenerative relay system, that is, a non-regenerative repeater having three stations (4 hops). It is a block diagram.

The relay system shown in FIG.
1, non-reproducing relay stations 302, 303, 304, and a reproducing wireless station 305. At this time, the transmitting radio station 30
The modulated signal generated in 1 is transmitted to the non-regenerative relay station 302 which is the next wireless station using the transmitting antenna 306. In the non-regenerative relay station 302, the modulated signal is received by the receiving antenna 3
07, 308, frequency-converted to an intermediate frequency band, diversity-combined, corrected for variations in reception level due to the propagation path, frequency-converted again to a radio frequency band, amplified to a required level, and then transmitted to the next radio. It is sent to the non-regenerative relay station 303 which is a station using the transmitting antenna 309. The non-regenerative relay station 303 receives the modulated signal using the receiving antennas 310 and 311, processes the received modulated signal in the same procedure as the non-regenerative relay station 302, and uses the transmitting antenna 312 to perform the next non-regenerative relay station. Send to 304. In the non-regenerative relay station 304,
The reception antennas 313 and 314 are used to receive the modulated signal, the reception modulation signal is processed by the same procedure as the non-regenerative repeater station 302, and the transmitting antenna 315 is used to reproduce the regenerated radio station 305.
Send to. In this way, the non-regenerative multi-relayed modulated signal is received and demodulated by the regenerative radio station 305 having the demodulator and the waveform equalizer via the receiving antennas 316 and 317. The additive noise of the adjacent channel passing interference generated in the non-regenerative repeater stations 302, 303, 304 is regenerated wireless station 305.
Are collectively compensated by the waveform equalizer provided in.

[0024]

As described above, according to the present invention,
Adjacent channels generated in the non-regenerative relay station by using the output signal of the upper heterodyne or the lower heterodyne in frequency conversion in the transmitter / receiver of the non-regenerative relay station and further synchronizing the transmission / reception local signal in the non-regenerative relay station. The additive noise of passing interference can be waveform distortion. This makes it possible to collectively compensate for additive noise due to adjacent channel passing interference in a reproducing radio station having a demodulator and a waveform equalizer.

From the above, the wireless communication system of the present invention can maintain the transmission quality almost the same as that of the regenerative digital wireless relay system, and has an effect that a significant cost reduction can be realized by not having a modulator / demodulator.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an exemplary embodiment of the present invention.

FIG. 2 is a diagram showing frequency allocation in the non-regenerative relay station of FIG.

FIG. 3 is a block diagram showing a configuration of an adaptation example of the present invention.

FIG. 4 is a block diagram showing a configuration example of a conventional reproduction digital wireless relay system.

FIG. 5 is a diagram showing a frequency allocation example of a conventional example.

FIG. 6 is a diagram illustrating the occurrence of adjacent channel passing interference in the conventional example.

FIG. 7 is a diagram for explaining adjacent channel passing interference in the conventional example.

[Explanation of symbols]

1 Reference Frequency Oscillator 2 Phase Comparator 3 Low Pass Filter 4 Voltage Controlled Oscillator 5 Divider 6-11 Phase-locked Oscillator 12-20 Frequency Converter 21, 22, 23 Transmission Amplifier 61-69 Band Pass Filter 101-103 Modulation Devices 104 to 106, 121 to 123 Transmitting device 107, 124 Multiplexing device 108, 125 Transmitting antenna 109, 110, 126, 127 Receiving antenna 111, 128 Demultiplexing device 112 to 114, 129 to 131 Receiving device 115 to 117, 132 ~ 134 Diversity combiner 118-120, 135-137 Automatic gain control circuit 138-140 Demodulator 141-143 Waveform equalizer 144 Transmitting radio station 145 Non-regenerating relay station 146 Reproducing wireless station 301 Transmitting wireless station 302-304 Non-reproducing Relay station 305 Reproduction radio station 30 6,309,312,315 Transmission antennas 307,308,310,311,313,314,3
16,317 Reception antennas 401 to 409 Modulators 410 to 412, 454 to 456 Transmission devices 413, 457 Multiplexing devices 414, 458 Transmission antennas 415, 416, 459, 460 Reception antennas 417, 461 Demultiplexing devices 418 to 420, 462 ~ 464 Receiver 421-423,465-467 Diversity combiner 424-426,468-470 Automatic gain control circuit 427-435,471-479 Demodulator 436-444,480-488 Waveform equalizer 445-453 Modulator 489 Transmission radio station 490 Regeneration relay station 491 Regeneration radio station 601 and 602 Reception antenna 603 Demultiplexing device 604 to 606 Reception device 607 to 609 Diversity combining device 610 to 612 Automatic gain control circuit 613 to 615 Transmission device 617 Transmission Container

Claims (1)

[Claims] 1. A transmission radio station having a modulator, a reproduction radio station having a demodulator and a waveform equalizer corresponding to the modulator, a frequency conversion function, and a function of amplifying to a required transmission level. In a hybrid relay system comprising a non-regenerative relay device and at least one non-regenerative relay station provided between the transmission wireless station and the regenerative wireless station, in the non-regenerative relay station, in the frequency conversion function. For a plurality of transmitted / received local signals to be used, frequency generating means for selecting the output signal of all of the upper heterodyne or lower heterodyne to generate a frequency, a reference frequency oscillator, and a frequency based on the output signal of the reference frequency oscillator. Generating a plurality of transmission / reception local signals used for conversion, and synchronizing the transmission / reception local signals of all systems in the non-regenerative repeater station. A transmission / reception local signal generation / synchronization means is provided, and noise compensation means for collectively compensating the addition of interference noise generated in the non-regeneration relay station by the waveform equalizer is provided in the regenerative radio station, With respect to a plurality of transmission / reception local signals by the generation means, all of the upper heterodyne or lower heterodyne output signals are selected and generated, and the transmission / reception local signal generation synchronization means generates a plurality of transmission / reception local signals of the non-regenerative repeater station. A radio communication system, wherein the noise is generated and synchronized, and the interference noise generated in the non-regeneration relay station is collectively compensated in the regeneration radio station by the noise compensating means.