JPH02159831A - Interference wave eliminating reception system - Google Patents

Abstract

PURPOSE:To eliminate an interference wave economically by providing a reflection mirror antenna or the like having a sub primary radiator receiving an interference wave coming from a direction different from that of a desired wave and a main primary radiator receiving the desired wave. CONSTITUTION:A desired wave R1 and an interference wave R2 coming to a parabolic antenna 10 are focused by a parabolic reflection mirror 11, received by primary radiators 12, 13 and subject to frequency conversion into an intermediate frequency signal via receivers 21, 22. Then the amplitude and phase of the intermediate frequency signal in the output of the receiver 22 are controlled by a variable coupler 31 and the copy signal of the interference component of the wave R2 included in the intermediate frequency signal of the output of the receiver 21 is formed. Succeedingly, a subtractor 30 subtracts a copy signal of the output of the coupler 31 from the intermediate frequency signal at the output of the receiver 21 and inputs it to a demodulator 40 and a base band signal is outputted. Then an error signal and the base band signal are subject to correlation via an error signal detector 50 and a correlation detector 51 and the correlation detection value is outputted to the coupler 31. Thus, the interference component of the wave R2 is eliminated from the base band signal and the interference wave is eliminated economically.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an interference wave cancellation reception system, and more particularly to an interference wave cancellation reception system for interference caused by interference waves arriving from a direction different from that of a desired wave.

[Conventional technology]

In the conventional interference wave removal reception method, the desired wave and the interference wave are received separately by the main antenna and the sub-antenna, and the main antenna is controlled by a variable coupler that controls the amplitude and phase of the received signal of the interference wave received by the sub-antenna. A replica signal of the interference component received by the desired signal received by the antenna is created, and the replica signal is subtracted from the desired signal using a subtracter to remove the interference component. The control signal input to the variable coupler can be obtained by correlating the received signal of the interference wave with the output signal of the subtracter. Further, the operation of creating a duplicate signal output from the variable coupler and subtracting the received signal of the desired wave from the duplicate signal is normally performed in an intermediate frequency band. The correlation detection operation between the received signal of the interference wave and the output signal of the subtracter is performed in the baseband band or intermediate frequency band.

Details of this correlation detection operation in the baseband band are described in, for example, Japanese Patent Laid-Open No. 58-131852. For details of this correlation detection operation in the intermediate frequency band, see, for example, Japanese Patent Application Laid-Open No. 58-131853.
It is stated in the No.

[Problem to be solved by the invention]

The above-described conventional interference wave cancellation reception system has the disadvantage that it is expensive because it requires a sub antenna for each arrival direction of each interference wave, independent of the main antenna that receives the desired wave.

SUMMARY OF THE INVENTION An object of the present invention is to provide an economically viable interference wave cancellation reception system.

[Means to solve the problem]

In the interference wave removal reception method of the present invention, an interference wave that comes from a direction different from that of the desired wave and interferes with the desired wave is received separately from the desired wave, and the received signal of the desired wave is received. In an interference wave removal reception method in which a replica signal of an interference component is created from a received signal of the interference wave and the replica signal is used to remove the interference component from the received signal of the desired wave, a reflecting mirror is combined with the reflecting mirror. The antenna includes a reflecting mirror antenna having a main primary radiator that receives the desired wave and a sub primary radiator that is combined with the reflecting mirror and receives the interference wave.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

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

The interference wave removal reception system shown in FIG.
It is configured to include a subtracter 30, a variable coupler 31, a demodulator 40, an error signal detector 50, and a correlation detector 51.

Next, the operation of this interference wave cancellation reception system will be explained.

First, from different directions, the parabolic antenna 10 is
Desired wave R3 and interference wave R2 arrive. The desired wave R1 is
It is focused by the parabolic reflector 11, and the primary radiator 12'cS
Received. Similarly, the interference wave R2 is focused by the parabolic reflector 11 and received by the primary radiator 13.

The receiver 21 uses the local oscillation signal input from the local oscillator 20 to frequency-convert the received signal input from the primary radiator 12 into an intermediate frequency signal. Similarly, the receiver 22 uses the local oscillation signal input from the local oscillator 20 to
The received signal input from the secondary radiator 13 is frequency-converted into an intermediate frequency signal.

The desired wave R1 received by the parabolic antenna 10 is an interference wave R
Since the intermediate frequency signal outputted by the receiver 21 contains the interference component of the interference wave R3,
The variable coupler 31 controls the amplitude and phase of the intermediate frequency signal output by the receiver 22 to create a replica signal of the interference component of the interference wave R2 contained in the intermediate frequency signal output from the receiver 21.

The subtracter 30 subtracts the duplicate signal output from the variable coupler 31 from the intermediate frequency signal output by the receiver 21. If the replicated signal output by the variable coupler 31 is ideal, the output of the subtracter 30 will not contain the interference component of the interference wave R2.

The demodulator 40 demodulates the intermediate frequency signal input from the subtracter 30 and outputs a baseband signal.

The error signal detector 50 detects the error from the normal value of the baseband signal input from the demodulator 40, and outputs the detection result as an error signal. The correlation detector 51 is connected to the receiver 2
The intermediate frequency signal inputted from the error signal detector 50 is demodulated to obtain a baseband signal, the correlation between this baseband signal and the error signal inputted from the error signal detector 50 is determined, and the detected correlation value is outputted to the variable coupler 31. The variable coupler 31 creates a duplicate signal by controlling the amplitude and phase of the intermediate frequency signal input from the receiver 22 so that the detected correlation value becomes small.

Therefore, the baseband signal output by the demodulator 40 is a desired baseband signal from which the interference component of the interference wave R2 has been removed. In addition, as the error signal detector 50 and the phase detector 51,
The interference wave reproducing circuit 26 and the control signal generating circuit 12 shown in FIG. 1 described in Publication No. 2 can be used.

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

The interference wave removal reception method shown in FIG. 2 is an interference wave removal reception method that removes interference from two interference waves, and the parabolic antenna 10 and subtracter 30 in the embodiment shown in FIG.
is replaced with a parabolic antenna 60 and a subtracter 70, and the receiver 23. It is configured by newly adding a variable combiner 32 and a correlation detector 52.

The parabolic antenna 60 is constructed by adding a primary radiator 61 to the parabolic antenna "10" shown in FIG.

The receiver 23 outputs the outputs of the primary radiator 61 and the local oscillator 20 to the variable coupler 32 and the correlation detector 52. The subtracter 70 inputs the outputs of the variable coupler 32 and variable coupler 31. The correlation detector 52 inputs the outputs of the error signal detector 50 and the receiver 23 and outputs them to the variable combiner 32 .

Next, the operation will be explained.

First, the desired wave R1 and interference waves R2 and R1 arriving from different directions are received by the primary radiators 12 and 13°61, respectively. Receivers 21, 22, 23 are primary radiators 12, 1
The frequency of the received signal of 3.61 is converted into an intermediate frequency signal using a local oscillation signal from the local oscillation signal generator 20. Receiver 2
The intermediate frequency signals output from the receivers 2 and 23 have their amplitudes and phases controlled by the variable couplers 31 and 32, respectively, and are input to the subtracter 70 as a replica signal of the interference component contained in the intermediate frequency signal of the receiver 21. Ru. A subtracter 70 subtracts the replicated signals, which are the outputs of the variable attenuators 31 and 32, from the intermediate frequency signal, which is the output of the receiver 21.

The demodulator 40 demodulates the intermediate frequency signal input from the subtracter 70 and outputs a baseband signal. Error signal detector 5
0 detects the error from the normal value of the baseband signal input from the demodulator 40, and outputs the detection result as an error signal. Correlation detectors 51 and 52 demodulate intermediate frequency signals inputted from receivers 22 and 23, respectively, to obtain baseband signals, and output the baseband signals and error signal detector 5.
Correlation with the error signal input from 0 is taken, and the detected correlation values are output to variable couplers 31 and 32, respectively. The variable couplers 31 and 32 control the amplitude and phase of the intermediate frequency signals inputted from the receivers 22 and 23, respectively, so as to reduce this correlation detection value and create a duplicate signal, so that the baseband signal output from the demodulator 40 The signal becomes a desired baseband signal from which the interference components of both interference waves R2 and R1 have been removed.

In the first and second embodiments described above, correlation detection between the received interference wave signal and the output signal of the subtracter is performed in the baseband band, but this correlation detection can also be performed in the intermediate frequency band. What can be done is as described above, and the present invention can be applied.

〔Effect of the invention〕

As explained above, the present invention uses a reflector antenna having a main primary radiator that receives a desired wave and a sub-primary radiator that receives interference waves arriving from a direction different from the desired wave. It is economical because there is no need to provide an independent sub-antenna for each direction of arrival of interference waves that interfere with waves, and only one reflecting mirror is required. The difference between the electrical length of the path to the subtracter and the path from the primary radiator that receives the interference wave to the subtracter is extremely small compared to the conventional example using an independent sub-antenna. This has the effect of making it easier to adjust the patience of both chambers.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a first embodiment of the present invention;
The figure is a block diagram showing a second embodiment of the present invention. 10.60...parabolic antenna, 11...
...parabolic reflector, 12,13.61...
Primary radiator, 20...Local oscillator, 21-23
...Receiver, 30°70...Subtractor,
31.32...Variable coupler, 40...Demodulator, 50...Error signal detector, 51.52...
...Correlation detector. Agent Patent Attorney Susumu Uchihara

Claims (1)

[Claims] An interference wave that comes from a direction different from that of the desired wave and interferes with the desired wave is received separately from the desired wave, and the interference component received by the received signal of the desired wave is replicated. An interference wave removal reception method in which a signal is generated from the received signal of the interference wave and the replica signal is used to remove the interference component from the received signal of the desired wave, comprising: a reflecting mirror; An interference wave removal reception method comprising: a reflecting mirror antenna having a main primary radiator that receives the interference wave; and a secondary primary radiator that is combined with the reflecting mirror and receives the interference wave.