JP2848160B2 - Wireless communication system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio communication system, and more particularly to a radio communication system which is required for collectively compensating for the addition of interference noise generated in a non-regenerative relay station in a regenerative radio station having a demodulator and a waveform equalizer. The present invention relates to a means for frequency-synchronizing a transmission / reception local signal of each system of a non-regenerative relay station with a certain reference signal, and particularly to determination of the reference signal frequency.

[0002]

2. Description of the Related Art FIG. 6 is a block diagram showing a configuration example of a conventional regenerative digital radio relay system. FIG. 1 is a diagram taking three systems as an example.

[0003] First, a modulating device 60 in a transmitting radio station.
The modulated signals generated from 1, 602 and 603 are frequency-converted to predetermined radio frequency bands by transmitting apparatuses 604, 605 and 606, and then multiplexed in a radio frequency band by multiplexing apparatus 607. And transmitted to the playback radio station. The reproduction radio station receives the modulated signal transmitted from the transmission radio station using the reception antenna 609,
The signal is demultiplexed into each system by the demultiplexer 610 and the receiving device 6
11, 612, and 613 to perform frequency conversion to an intermediate frequency band. The modulated signals frequency-converted to the intermediate frequency band are amplified to predetermined levels by automatic gain controllers 614, 615, and 616, and are demodulated to respective demodulators 617, 618,
The signal transmitted by 619 is reproduced. The reproduced signal includes waveform distortion generated in the propagation path, and the waveform distortion is compensated for using the waveform equalizers 620, 621, and 622.

[0004]

However, in the above-mentioned conventional configuration, since a modem is required for each relay station, the configuration of the relay device is complicated, and there are problems in power consumption and economy.

In order to solve these problems, the present invention employs a non-regenerative relay system which does not require a modem in the relay station, and further synchronizes each local signal transmitted and received in the non-regenerative relay station by synchronizing each signal. A regenerative radio station having a demodulator and a waveform equalizer collectively compensates for interference noise added by a non-regenerative relay station, and provides communication equivalent to the transmission quality of the regenerative relay scheme. In particular, an object of the present invention is to provide a wireless communication system capable of realizing synchronization of transmission and reception local signals in a non-regenerative relay station with a simple configuration.

In the present invention, the additive interference noise that is collectively compensated for is interference passing through adjacent channels. In the interference, when the modulated signal is demultiplexed and multiplexed in the non-regenerative relay station, the self-modulated signal (not necessary for an adjacent signal) is used when the signal is demultiplexed because the demultiplexing and multiplexing filter has a wide band. The signal is also input to the adjacent signal transmission type, and this is a desired signal again at the time of multiplexing, which is interference caused by multiplexing with the original desired signal.

[0007]

SUMMARY OF THE INVENTION The present invention provides a transmitting radio station having a modulator, a reproducing radio station having a demodulator and a waveform equalizer corresponding to the modulator, and a propagation path for a received signal. At least one non-regenerative relay station provided between the transmitting radio station and the regenerating radio station, the non-regenerative relay station having a non-regenerative relay apparatus having a function of correcting the influence of the above, a frequency conversion function, and a function of amplifying to a required transmission level. In a hybrid relay system comprising: a non-regenerative relay station, frequency generating means for generating a frequency that is a common divisor of the frequencies of a plurality of transmission and reception local signals used for the frequency conversion function, and multiplying the output of the frequency generating means A transmission / reception local signal generation / synchronization means for generating a plurality of transmission / reception local signals used for the frequency conversion function and synchronizing the transmission / reception local signals; The noise compensation means for compensating the additive interference noise generated in a non-regenerative repeater station by the waveform equalizer that is characterized in that provided.

[0008]

According to the present invention having the above configuration, a frequency that is a common divisor of the frequencies of the plurality of transmission / reception local signals generated by the frequency generation means is multiplied by the transmission / reception local signal generation / synchronization means and the plurality of non-regenerative relay stations are multiplied. , And synchronizes the transmitted and received local signals. Then, the regenerative radio station collectively compensates for adjacent channel passing interference noise generated in the non-regenerative relay station by the noise compensating means.

Therefore, according to the present invention, it is possible to provide communication equivalent to the transmission quality of the regenerative relay system, and not only to realize a significant cost reduction by not having a modem, but also to realize a non-regenerative relay station. Synchronization of transmission and reception local signals can be realized with a simple configuration.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the first embodiment of the present invention. It should be noted that the relay system shown in the figure shows an example composed of a transmitting radio station, a non-regenerative relay station, and a regenerative radio station, that is, a case where there is one non-regenerative relay station (two hops) will be described.

In FIG. 1, a transmitting radio station modulates a modulator 10.
Signals modulated by 1, 102, and 103 are frequency-converted into radio frequency bands via transmitting devices 104, 105, and 106, and then multiplexed by a multiplexing device 107 and transmitted by a transmitting antenna 1.
08 to the non-regenerative relay station 156. At this time, the center frequencies of the signals modulated by the modulation devices 101, 102, and 103 in the intermediate frequency band are all the same.

The modulated signal received by the non-regenerative relay station 156 using the receiving antenna 109 is split into each system by the splitter 110 and then received by the receiver 11 for each system.
1, 112 and 113. Receiving devices 111, 11
The modulated signals received by the phase locked oscillators 117, 121, and 125 receive the output signal of the reference frequency oscillator 126 and generate a required reception local signal.
Is converted to the same intermediate frequency band as the signal transmitted from the transmitting wireless station via the mixers 114, 118 and 122.

The fluctuation of the reception level due to the propagation path is corrected by the automatic gain control circuits 116, 120, 124 via the band pass filters 115, 119, 123, and is input to the transmission devices 128, 129, 130 at a predetermined level.

FIG. 4 shows the phase locked oscillator 11 of FIG.
7, 121, 125, 133, 136 and 139 are shown. In the figure, a signal from a reference frequency oscillator 126 passes through a signal distributor 127, and then passes through a phase comparator 40.
1 to generate an output voltage corresponding to the phase difference from the output signal of the frequency divider 404. This output voltage is supplied to a phase comparator 40 by a low-pass filter called a loop filter 402.
Unnecessary components included in the output of the filter 1 are removed, and the output of the filter is a voltage controlled oscillator (hereinafter abbreviated as VCO) 403.
To generate a transmission / reception local signal necessary for frequency-converting the modulated signal into a predetermined frequency band. VCO4
03 is divided by the frequency divider 404 to the output frequency of the reference frequency oscillator 126, and the phase comparator 40
Enter 1 The VCO 403 outputs a radio frequency according to the control signal voltage, and the reference frequency oscillator 126
A frequency lower than the transmission frequency of 403 is output.

Next, the modulated signals input to the transmitters 128, 129 and 130 receive the output signal of the reference frequency oscillator 126 as an input, and output signals of the phase locked oscillators 133, 136 and 139 for generating required transmission local signals. The frequency is again converted to a radio frequency band via mixers 131, 134 and 137. Each frequency-converted modulated signal is amplified to a predetermined level using amplifiers 132, 135, and 138. Modulated signals output from transmitting devices 128, 129, and 130 are multiplexed by multiplexing device 140, and
The signal is transmitted to a reproducing radio station having a demodulation device and a waveform equalizer by using 41. In the reproducing radio station, the receiving antenna 14
2 is demultiplexed into each system by the demultiplexer 143, and the output signal is
4, 145, 146. Receiver 144, 14
The modulated signals frequency-converted to predetermined intermediate frequency bands at 5,146 are passed through automatic gain controllers 147,148,149 to demodulators 150,151,152 for the respective modulated signals.
To enter. Waveform distortion included in the modulated signals frequency-converted into baseband signals by the demodulators 150, 151, 152 is compensated by the waveform equalizers 153, 154, 155.

FIG. 5 shows an example of transmission / reception frequency arrangement of the non-regenerative relay station 156 together with local frequencies. The determination of 126 output signal frequencies at this time is, for example, 4
Taking the GHz band as an example, the transmission and reception local frequency 3510,
3570,3630,3850,3910,3970M
Hz, a common divisor of 1MHz, 5MHz, 10MHz
Is selected. Further, taking the 6 GHz band as an example, the transmission and reception local frequencies 5825, 5885, 5945, 60
The common divisor of 85,6145,6205 MHz becomes 12
For the determination of the output signal frequency of 6, 1 MHz, 5 MHz and the like are selected, and 10 MHz which is a common divisor of the 4 GHz band cannot be used.

As described above, the output signal frequency of the reference frequency oscillator 126 is selected so as to be a common divisor of the frequency of the transmission / reception local signal of the non-regenerative relay station, and further, each of the phase locked oscillators 117, 121, 125, 133, 136,13
The required local signal can be obtained by arbitrarily adjusting the multiplication factor of 9, and the transmission / reception local signal of the non-regenerative relay station can be synchronized. Thereby, the adjacent channel passing interference generated in the non-regenerative relay station becomes equivalent to the waveform distortion,
Demodulators 150, 151, 152 and waveform equalizer 153,
It can be completely compensated by the regenerating radio station having 154 and 155.

FIG. 2 is a block diagram showing the configuration of the second embodiment of the present invention. This embodiment differs from the first embodiment in FIG. 1 in that the transmission / reception local signal for frequency conversion in the non-regenerative relay station 156 has the same frequency and the intermediate frequency of each system after the frequency conversion has a different frequency. is there. Thereby, the phase locked oscillators 157 can be integrated.

FIG. 3 is a block diagram showing a configuration when the wireless communication system of the present invention is applied. This figure shows a case where the number of non-regenerative relay stations is three (four hops). This system is basically a system aiming at an economic effect, and the effect appears at the time of multiple relays.

The relay system shown in FIG.
1. Non-regenerative relay stations 302, 303, 304 and a regenerative radio station 305. At this time, the transmitting wireless 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 transmission antenna 306. The non-regenerative relay station 302 transmits the modulated signal to the receiving antenna 3
07, the frequency is converted to an intermediate frequency band, the fluctuation of the reception level due to the propagation path is corrected, the frequency is converted again to the radio frequency band, and the signal is amplified to a required transmission level. The transmission antenna 308 is provided to the relay station 303.
Send using

In the non-regenerative relay station 303, the receiving antenna 3
09, and uses the same procedure as the non-regenerative relay station 302 to process the received modulated signal.
The next non-regenerative relay station 304 is transmitted using 0. The non-regenerative relay station 304 receives the modulated signal using the receiving antenna 311, processes the received modulated signal in the same procedure as the non-regenerative relay station 302, and sends it to the next regenerative relay station 304 using the transmitting antenna 312. The non-regeneratively relayed modulated signal is supplied to a regenerative radio station 305 having a demodulator and a waveform equalizer.
Is received via the receiving antenna 313 and demodulated.
The additive noise of the adjacent channel passing interference generated in the non-regenerative relay station is collectively compensated by a waveform equalizer included in the regenerative radio station.

[0022]

As described above, according to the present invention,
By generating each transmission / reception local signal of the non-regenerative relay station by multiplying from the output signal of the reference frequency oscillator that outputs a frequency that is a common divisor of each transmission / reception local signal frequency,
The transmission and reception local signals are synchronized, and the additive noise of the adjacent channel passing interference generated in the non-regenerative relay station can be used as the waveform distortion. This makes it possible to collectively compensate for additive noise due to adjacent channel passing interference in a reproduction wireless station having a demodulator and a waveform equalizer.

As described above, the non-regenerative relay system described in the present invention can maintain almost the same transmission quality as the regenerative digital wireless relay system, and can realize a significant cost reduction by not having a modem. In particular, according to the present invention, there is obtained an effect that synchronization of each transmission / reception local signal in the non-regenerative relay station can be realized with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a block diagram showing a second embodiment of the present invention.

FIG. 3 is a block diagram showing an example to which the wireless communication system of the present invention is applied.

FIG. 4 is a block diagram illustrating a configuration of a phase locked oscillator in FIG. 1;

FIG. 5 is a diagram showing an example of transmission and reception frequency arrangement of a non-regenerative relay station used in the first embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration example of a conventional regenerative digital wireless relay system.

[Explanation of symbols]

101, 102, 103 Modulating devices 104, 105, 106, 128, 129, 130 Transmitting devices 107, 140 Multiplexing devices 108, 141 Transmitting antennas 109, 142 Receiving antennas 110, 143 Demultiplexing devices 111, 112, 113, 144 145, 146 Receiver 114, 118, 122, 131, 134, 137 Mixer 115, 119, 123 Bandpass filter 116, 120, 124 Automatic gain control circuit 117, 121, 125, 133, 136, 139 Phase-locked oscillator 126 Reference Frequency oscillator 127 Signal distributor 132, 135, 138 Amplifier 147, 148, 149 Automatic gain controller 150, 151, 152 Demodulator 153, 154, 155 Waveform equalizer 156 Non-regenerative repeater station 157 Phase-locked oscillator 301 Transmission radio 302, 303, 304 Non-regenerative relay station 305 Regenerative radio station 306, 308, 310, 312 Transmitting antenna 307, 309, 311, 313 Receiving antenna 401 Phase comparator 402 Loop filter 403 Voltage controlled oscillator 404 Divider 601, 602, 603 Modulator 604,605,606 Transmitter 607 Combiner 608 Transmit antenna 609 Receiving antenna 610 Demultiplexer 611,612,613 Receiver 614,615,616 Automatic gain controller 617,618,619 Demodulator 620,621 , 622 Waveform equalizer

Continuation of the front page (56) References JP-A-4-35140 (JP, A) JP-A-6-125283 (JP, A) IEICE Transactions Vol. J75-B-2, no. 8 (Heisei 4-8-25) p. 508-514 Proceedings of the 1990 IEICE Autumn National Convention, Volume 2 [1990-9-15] p. 2-335 Proceedings of the 1990 IEICE Spring Conference, Volume 2 [1990-3-5] p. 2-398 Transactions of the Institute of Electronics, Information and Communication Engineers, Vol. J74-B-2, no. 10 (Heisei 3-10-25) p. 566-568 NTT R & D Vol. 44, No. 3 (1995) p. 277-282 NTT R & D Vol. 44, No. 3 (1995) p. 283-288 (58) Fields surveyed (Int. Cl. ⁶ , DB name) H04B 3/00-3/18 H04B 7/005 H04B 7/14-7/15 H04J 1/04 JICST file (JOIS)

Claims (1)

(57) [Claims] 1. A transmitting radio station having a modulator, a reproducing radio station having a demodulator and a waveform equalizer corresponding to the modulator, a function of correcting the influence of a propagation path on a received signal, A hybrid relay system comprising a non-regenerative relay device having a conversion function and a function of amplifying to a required transmission level, comprising at least one non-regenerative relay station provided between the transmitting radio station and the regenerative radio station. In the non-regenerative relay station, frequency generating means for generating a frequency that is a common divisor of the frequencies of the plurality of transmission and reception local signals used for the frequency conversion function, and the frequency conversion function by multiplying the output of the frequency generation means A plurality of transmission / reception local signals used for generating a transmission / reception local signal generation and synchronization means for synchronizing the transmission / reception local signals are provided. Noise compensating means for compensating for addition of interference noise generated in the non-regenerative relay station by the waveform equalizer is provided, and a frequency which is a common divisor of a plurality of transmission and reception local signals generated by the frequency generating means is set to the frequency. A plurality of transmission / reception local signals of the non-regenerative relay station are generated by multiplying by the transmission / reception local signal generation / synchronization means, and the transmission / reception local signals are synchronized, and interference generated in the non-regenerative relay station at the reproduction radio station is generated. A wireless communication system, wherein noise is collectively compensated for by the noise compensating means.