JP2682345B2 - Compensation system for cross polarization interference generated at non-regenerative wireless relay stations - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to means for collectively compensating additive noise of cross polarization interference generated in a non-regenerative radio relay station in a radio station having a demodulator and a cross polarization interference compensator.

[0002]

2. Description of the Related Art FIG. 5 shows an example of the configuration of a conventional regenerative digital radio relay system, which shows polarization planes (V / H) orthogonal to each other.
FIG. 3 is a block diagram showing an example of two channels having polarized waves). The modulated signals generated by the modulators 101 and 102 in the transmitting radio station are frequency-converted into a predetermined radio frequency band by the transmitting devices 103 and 104, multiplexed by the demultiplexing device 105 in the radio frequency band, and then the transmitting antenna 106. Is transmitted to the next wireless station. In the reproducing radio station, the modulated signal sent from the transmitting radio station is received using the receiving antenna 131, demultiplexed into each channel by the demultiplexing device 132, and frequency conversion is performed to the intermediate frequency band using the receiving devices 133 and 134. To do. The modulated signal frequency-converted to the intermediate frequency band is amplified to a predetermined level by the automatic gain control circuits 135 and 136, and reproduced as signals transmitted by the demodulation devices 137 and 138, respectively. The regenerated signal is used by the waveform equalizer 13 in order to compensate for cross polarization interference generated in the propagation path.
After passing through 9, 140, cross polarization interference compensator 141,
The reference signal is extracted from the polarization side signal using 142.
It is compensated via the adders 143 and 144.

[0003]

In such a conventional structure, since each relay station requires a modulation / demodulation device, the structure of the relay device is complicated, and there are problems in power consumption and economical efficiency. The present invention adopts a non-regenerative repeater system that eliminates a modulator / demodulator in a relay station in order to solve the above problems, and further reproduces interference noise added in each non-regenerative repeater station by using a modulator / demodulator and an interference compensator. The objective is to provide communication equivalent to the transmission quality of the regeneration relay system by performing collective compensation at the wireless station. In the present invention, the additive interference noise collectively compensated is cross polarization interference. Cross polarization interference is a plane of polarization (V polarization, H polarization) orthogonal to each other in the same frequency band.
This is interference caused by leaking from the V polarized wave to the H polarized wave or from the V polarized wave to the H polarized wave when a signal is transmitted using.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a transmitting radio station having a modulating device, a reproducing radio station having a demodulating device and a cross polarization interference compensator corresponding to the modulating device, and the transmitting radio station. And at least one non-regeneration relay station between the non-regeneration relay station and the non-regeneration relay station.
A reception frequency converter that synchronizes two modulated signals of polarized wave and V polarization and converts them into an intermediate frequency, and an automatic gain that corrects a level fluctuation due to a propagation path of each signal output from the reception frequency converter An amplifier, a transmission frequency converter for synchronizing and converting each signal output from the automatic gain amplifier to a required transmission frequency, and an amplifier for amplifying each signal output from the transmission frequency converter to a required transmission level. In the hybrid relay system including a transmission amplifier, the transmission wireless station has means for phase-synchronizing two modulated signals having H polarization and V polarization orthogonal to each other, Is provided for each of the reception frequency converter and the transmission frequency converter for one reference frequency oscillator and two modulation signals of H polarization and V polarization, respectively. A phase-locked oscillator, the output signal of the reference frequency oscillator is branched and input to each of the phase-locked oscillators, each output of the phase-locked oscillator is applied to the frequency converter, and The regenerative radio station is configured to achieve phase synchronization between the modulated signals, and the regenerative radio station collectively compensates the additive noise of the cross polarization interference generated in the non-regenerative relay station by the cross polarization interference compensator. It is characterized by having. Further, in the hybrid relay system according to the present invention, the transmitting radio station has means for phase-synchronizing two modulated signals having an H polarization and a V polarization orthogonal to each other. Includes, for each of the reception frequency converter and the transmission frequency converter, one reference frequency oscillator and one phase-locked oscillator that receives the output of the reference frequency oscillator. Is branched and applied to the frequency converter so as to achieve phase synchronization between the two modulated signals, and the regenerative radio station adds additive noise of cross polarization interference generated in the non-regenerative relay station. It may have means for collectively compensating for the above with a cross polarization interference compensator. Further, according to the present invention, in the hybrid relay system, the transmitting radio station has means for phase-synchronizing two modulated signals having an H polarization and a V polarization which are orthogonal to each other. Comprises one reference frequency oscillator and a phase-locked oscillator respectively provided for the two modulation signals of the H polarization and the V polarization for the reception frequency converter and the transmission frequency converter, respectively. An output signal of the reference frequency oscillator is branched and input to each of the phase-locked oscillators, each output of the phase-locked oscillator is applied to the frequency converter, and phase-locked between the two modulation signals. The playback radio station is
There may be provided means for collectively compensating additive noise of cross polarization interference generated in the non-regenerative relay station by the cross polarization interference compensator.

[0005]

According to the above structure, the modulated signals are frequency-converted by using the transmission / reception local signals whose phases are synchronized with each other, so that the cross polarization interference generated in the non-regenerative repeater station is added to the modulated signals with coherency. Therefore, it becomes possible to collectively compensate in the regenerative radio station having the cross polarization interference compensator.

[0006]

FIG. 1 is a block diagram showing the configuration of a first embodiment of the present invention. The relay system shown in FIG.
An example of the non-regenerative relay station and the regenerative wireless station is shown. Hereinafter, a case where the non-regenerative relay station is one station (two hops) will be described. In the figure, the transmitting radio station is provided with a modulator 10
Signals modulated by 1, 102 are transmitted by transmitting apparatus 103,
After frequency conversion to a radio frequency band via 104, the demultiplexing device 105 performs polarization multiplexing and transmission to the non-regenerative relay station 145 using the transmission antenna 106. In the demultiplexing device 105, the output signal of the modulator 101 is H-polarized, and the output signal of the modulator 102 is V-polarized and combined in the same frequency band with mutually orthogonal polarization planes. Since the cross polarization interference compensator has a baseband configuration, the modulated signals of both polarizations and the transmission local signal of the transmission wireless station are synchronized between the polarizations. The signal received using the reception antenna 107 in the non-regenerative repeater station 145 is demultiplexed by the demultiplexing device 108 into channels of each polarization, and then input to the receiving devices 109 and 110 for each channel. The modulated signals received by the receivers 109 and 110 receive the output signal of the reference frequency oscillator 113 as input, and output signals of phase-locked oscillators (PLO) 112 and 115 that generate a required received local signal and the mixers 111 and 114. The frequency is converted to the intermediate frequency band. FIG. 6 shows a configuration example of the phase-locked oscillator (PLO) 606 required for synchronizing the transmission / reception local signals.
In the figure, the signal from the reference frequency oscillator 601 is input to the phase comparator 602 and an output voltage corresponding to the phase difference from the output signal of the frequency divider 605 is generated. A low-pass filter called a loop filter 603 removes unnecessary components contained in the output of the phase comparator from the output voltage, and the filter output controls the voltage controlled oscillator (VCO) 604 to output the modulated signal to a predetermined frequency band. Generate the transmit / receive local signal required for frequency conversion to. One of the outputs of the VCO 604 is divided by the frequency divider 605 into the reference frequency oscillator 601.
The frequency is divided up to the output frequency of and input to the phase comparator 602. The VCO 604 outputs a radio frequency according to the control signal voltage, and the reference frequency oscillator 601 outputs a low frequency as compared with the oscillation frequency of the VCO 604. In this way, by using one reference frequency oscillator, branching its output signal into a plurality of signals, and inputting them into each PLO, it is possible to generate transmission / reception local signals that are phase-synchronized with each other. The output of the reference frequency oscillator 113 input to the PLOs 112 and 115 is amplified to a required level by using the amplifier 116 to compensate for the level drop due to the branch. The fluctuation of the reception level due to the propagation path is caused by the automatic gain control circuits 117 and 118.
Are absorbed by the transmitters 119 and 120 at a predetermined level.
To enter. In the transmitters 119 and 120, a reference signal oscillator 124 different from the reference frequency oscillator 111 is used, and its output signal is branched and input to the PLOs 123 and 127. The modulated signals input to the transmitters 119 and 120 are frequency-converted again into the radio frequency band via the phase-synchronized transmission local signals that are PLO 123 and 127 outputs and the mixers 121 and 125. Where PLO12
The reference frequency oscillator 124 output input to 3,127 is
It is amplified to a required level using an amplifier 128 to compensate for the level reduction due to the branch. The frequency-converted modulated signals are amplified to a predetermined transmission level by using amplifiers 122 and 126, are combined by a predetermined demultiplexing device 129 in a predetermined plane of polarization, and are cross-polarized with a demodulating device using a transmitting antenna 130. It is transmitted to a regenerative radio station having a wave interference compensator. At this time, the transmitter / receiver (109, 11) of the non-regenerative relay station 145
Since the transmission local signal and the reception local signal in (0, 119 and 120) are respectively phase-synchronized with each other, cross polarization interference is added to the modulation signal while maintaining coherency. In the reproducing radio station, the modulated signal received by using the receiving antenna 131 is demultiplexed by the demultiplexing device 132 into channels of each polarization, and the output signals thereof are received by the receiving devices 133, 13.
Enter in 4. The modulated signals frequency-converted to the predetermined intermediate frequency band by the receiving devices 133 and 134 are input to the demodulating devices 137 and 138 via the automatic gain control circuits 135 and 136. The cross polarization interference included in the modulated signal that has been frequency-converted into the baseband signal by the demodulation devices 137 and 138 is transmitted through the waveform equalizers 139 and 140, and the cross polarization interference compensators 141 and 142 are used. The reference signal is extracted from the modulated signal of and is compensated through adders 143 and 144. FIG. 2 is a block diagram showing the configuration of the second embodiment of the present invention. This embodiment is different from the first embodiment in FIG. 1 in that each transmitting / receiving device 109, 1 in the non-regenerative relay station 145 is different.
19 have reference oscillators 113 and 124 respectively, and output the output signals of the reference frequency oscillators 113 and 124 to the PLO 11
2 and 123 are respectively input to generate a transmission / reception local signal. The transmission / reception local signal generated in this way is branched, and the modulated signal is frequency-converted into a predetermined frequency band through the mixers 111, 114, 121, and 125. At this time, the received local signal input to the mixer 114 in the receiving device 110 and the mixer 1 in the transmitting device 120.
The transmission local signal input to 25 is amplified to a predetermined level by using amplifiers 116 and 128 in order to compensate for the level decrease due to branching. FIG. 3 is a block diagram showing the configuration of the third exemplary embodiment of the present invention. This embodiment is different from the first embodiment in FIG. 1 in that the reference frequency oscillators 113 and 113A are respectively provided in the receivers 109 and 110, and the oscillators are duplicated by switching them using a switch 301. Out. Thereby, for example, the reference frequency oscillator 1
If 13 fails, switch 301 switches to another reference frequency oscillator 113A. The output signal of the switch 301 is branched and input to the PLOs 112, 115, 123 and 127. At this time, PLO 112, 115, 1
The inputs to 23 and 127 are amplified to a predetermined level by using amplifiers 116, 128 and 128A in order to compensate for the level drop due to the branching of the output signal of the reference frequency oscillator (113 or 113A). Using the transmission / reception local signals generated in this way, the mixers 111, 114, 12
The modulated signal is frequency-converted into a predetermined frequency band via 1 and 125. FIG. 4 shows the configuration of the fourth embodiment of the present invention and is a block diagram showing the configuration of a multi-relay non-regenerative relay system. The non-regenerative repeater system is basically a system aiming at an economic effect, and the effect appears when there are many repeaters. The relay system shown in the figure includes a transmission wireless station 401, non-regenerative relay stations 402 and 403, and a regenerative wireless station 404. At this time, the modulated signal modulated by the transmitting radio station is sent to the non-regenerating relay station 402 which is the next radio station using the transmitting antenna 405. In the non-regenerative relay station 402,
The modulated signal is received using the receiving antenna 406, amplified to a required transmission level, and then sent to the non-regenerative relay station 403 which is the next wireless station using the transmitting antenna 407. The non-regenerative relay station 403 receives the modulated signal using the receiving antenna 408, processes the received modulated signal in the same procedure as the non-regenerative relay station 402, and sends it to the next non-regenerative relay station using the transmitting antenna 409. . The modulated signal that is not regenerated and relayed in this way is a wireless station 404 having a demodulator and a waveform equalizer.
Is received via the receiving antenna 410 and demodulated.
The additive noise of cross polarization interference generated in the non-regenerative relay station is collectively compensated by the cross polarization interference compensator included in the regenerative radio station.

[0007]

As described above, according to the present invention, one or a plurality of reference frequency oscillator outputs are branched into a plurality of outputs, and the outputs are input to a phase-locked oscillator provided in a transmitter / receiver to transmit / receive local signals in phase with each other. By generating the signal, it is possible to perform frequency conversion of the modulation signals that are phase-synchronized with each other, and it is possible to add additive noise of cross polarization interference generated in the non-regenerative relay station to the modulation signal while maintaining coherency. As a result, additive noise due to cross polarization interference can be collectively compensated for in a regenerative radio station having a demodulator and a cross polarization interference compensator. From the above, it can be said that the non-regenerative repeater system to which the compensation system of the present invention is applied can maintain almost the same transmission quality as the regenerative digital wireless repeater system, and can realize a significant cost reduction by not having the modulator / demodulator. effective.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of a system for compensating for cross polarization interference occurring in a non-regenerative wireless relay station according to the present invention.

FIG. 2 is a block diagram showing a second embodiment of a system for compensating for cross polarization interference occurring in a non-regenerative wireless relay station according to the present invention.

FIG. 3 is a block diagram showing a third embodiment of a compensation system for cross-polarization interference generated in a non-regenerative wireless relay station according to the present invention.

FIG. 4 is a block diagram showing a fourth embodiment of a system for compensating for cross polarization interference generated in a non-regenerative wireless relay station according to the present invention.

FIG. 5 is a block diagram showing a configuration example of a reproduction digital wireless relay system which is a conventional system.

FIG. 6 is a block diagram showing a phase-locked oscillator (PLO).

[Explanation of symbols]

101,102 Modulator 103,104,119,120 Transmitter 105,108,129,132 Demultiplexer 106,130 Transmit antenna 107,131 Receive antenna 109,110,133,134 Receiver 111,114,121,125 Mixer 112, 115, 123, 127 Phase-locked oscillator (P
LO) 113,113A Reference frequency oscillator 116,128,128A, amplifier 122,126 Transmission amplifier 117,118,135,136 Automatic gain control circuit 137,138 Demodulator 139,140 Waveform equalizer 141,142 Cross polarization interference Compensator 143, 144 Adder 145 Non-regenerative relay station 301 Switch 401 Transmission wireless station 402, 403 Non-regenerative relay station 404 Regenerative wireless station 405, 407, 409 Transmit antenna 406, 408, 410 Receive antenna 601 Reference frequency oscillator 602 Phase comparison 603 Loop filter 604 Voltage controlled oscillator (VCO) 605 Frequency divider 606 Phase locked oscillator (PLO)

Claims (3)

(57) [Claims] 1. A transmission radio station having a modulation device, a reproduction radio station having a demodulation device and a cross polarization interference compensator corresponding to the modulation device, and between the transmission radio station and the reproduction radio station. Has at least one non-regenerative relay station in
The non-regeneration relay device provided in the non-regeneration relay station includes a reception frequency converter that synchronizes two modulated signals of the H polarization and the V polarization, which are received from the transmission radio station and are orthogonal to each other, and converts them into an intermediate frequency. An automatic gain amplifier that corrects the level fluctuation of each signal output from the reception frequency converter due to the propagation path, and a transmission that synchronizes and converts each signal output from the automatic gain amplifier to a required transmission frequency In a hybrid relay system including a frequency converter and a transmission amplifier that amplifies each signal output from the transmission frequency converter to a required transmission level, the transmission wireless station includes an H-polarized wave and a V-polarized wave that are orthogonal to each other. The non-regenerative repeater has means for phase-synchronizing two modulated signals having polarized waves, and the non-regenerative repeater includes the reception frequency converter and the transmission frequency converter. Each of them is provided with one reference frequency oscillator and a phase-locked oscillator provided for each of the two modulation signals of the H polarization and the V polarization, and the output signal of the reference frequency oscillator is branched. Are input to the respective phase-locked oscillators, respective outputs of the phase-locked oscillators are applied to the frequency converter, and the two modulated signals are phase-locked with each other. Generated in the non-regenerative radio relay station, wherein the non-regenerative radio relay station has means for collectively compensating additive noise of cross-polarization interference generated in the non-regenerative relay station by the cross-polarization interference compensator. Cross polarization interference compensation system. 2. A transmitting radio station having a modulating device, a reproducing radio station having a demodulating device and a cross polarization interference compensator corresponding to the modulating device, and between the transmitting radio station and the reproducing radio station. Has at least one non-regenerative relay station in
The non-regeneration relay device provided in the non-regeneration relay station includes a reception frequency converter that synchronizes two modulated signals of the H polarization and the V polarization, which are received from the transmission radio station and are orthogonal to each other, and converts them into an intermediate frequency. An automatic gain amplifier that corrects the level fluctuation of each signal output from the reception frequency converter due to the propagation path, and a transmission that synchronizes and converts each signal output from the automatic gain amplifier to a required transmission frequency In a hybrid relay system including a frequency converter and a transmission amplifier that amplifies each signal output from the transmission frequency converter to a required transmission level, the transmission wireless station includes an H-polarized wave and a V-polarized wave that are orthogonal to each other. The non-regenerative repeater has means for phase-synchronizing two modulated signals having polarized waves, and the non-regenerative repeater includes the reception frequency converter and the transmission frequency converter. Each is provided with one reference frequency oscillator and one phase-locked oscillator receiving the output of the reference frequency oscillator, the output signal of the phase-locked oscillator is branched and applied to the frequency converter, The two modulated signals are configured to be phase-synchronized with each other, and the regenerative radio station collectively adds additive noise of cross polarization interference generated in the non-regenerative relay station by the cross polarization interference compensator. Compensation system for cross polarization interference generated in a non-regenerative radio relay station, characterized in that it has means for compensating for it. 3. A transmitting radio station having a modulating device, a reproducing radio station having a demodulating device and a cross polarization interference compensator corresponding to the modulating device, and between the transmitting radio station and the reproducing radio station. Has at least one non-regenerative relay station in
The non-regeneration relay device provided in the non-regeneration relay station includes a reception frequency converter that synchronizes two modulated signals of the H polarization and the V polarization, which are received from the transmission radio station and are orthogonal to each other, and converts them into an intermediate frequency. An automatic gain amplifier that corrects the level fluctuation of each signal output from the reception frequency converter due to the propagation path, and a transmission that synchronizes and converts each signal output from the automatic gain amplifier to a required transmission frequency In a hybrid relay system including a frequency converter and a transmission amplifier that amplifies each signal output from the transmission frequency converter to a required transmission level, the transmission wireless station includes an H-polarized wave and a V-polarized wave that are orthogonal to each other. The non-regenerative repeater includes a reference frequency oscillator and the reception frequency converter. And a phase-locked oscillator respectively provided for the two modulation signals of the H-polarized wave and the V-polarized wave for each of the transmission frequency converters, and the output signal of the reference frequency oscillator is branched. Each of the phase-locked oscillators is input, each output of the phase-locked oscillator is applied to the frequency converter, and the two modulated signals are configured to be phase-locked. The cross-polarization interference compensator collectively compensates additive noise of cross-polarization interference generated in the non-regeneration relay station, which is generated in the non-regeneration wireless relay station. Cross polarization interference compensation system.