JPH0490639A - Polarized wave shared receiver - Google Patents

Abstract

PURPOSE:To prevent the deterioration of communication quality by suppressing one arbitrary polarized wave to take out the signal of the other desired polarized wave when transmitting two polarized waves jointly. CONSTITUTION:A power feeding circuit 11 is set so that the signal with two polarized waves received by an antenna device 10 can be outputted to two output terminals respectively. A polarized wave selection circuit 20 suppresses one arbitrary polarized wave by controlling the phase and amplitude of an output signal from one output terminal of the power feeding circuit 11 to be synthesized to the output signal from the other output terminal, and takes out the other desired polarized wave. The signal of the other polarized wave taken out from the polarized wave selection circuit 20 is inputted to a receiver 30, and the one arbitrary polarized wave is received. Thus, the communication quality can be maintained without affected by cross polarized wave interference even at the time of the deterioration of cross polarized wave discrimination degree caused by a rainfall.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a polarization shared receiving device in wireless communication, and
The present invention relates to a polarization shared receiving device for a wireless transmission system that transmits two polarized waves in common.

[Conventional technology]

FIG. 4 shows an example of a configuration when performing conventional polarization sharing. 4
] is an antenna device that receives incoming radio waves and a polarization splitter 4 that separates signals according to the polarization of the received radio waves.
It consists of 8. 42 and 43 are output terminals for the polarized waves split by the polarization splitter 48 of the antenna device 41, and the output terminal 42 outputs one polarization split by the polarization splitter 48, for example, vertical polarization. The output terminal 43 corresponds to the other polarized wave split by the polarization splitter 48, for example, the horizontal polarized wave 2. 44 is a receiver of polarization 1, 45
is a receiver corresponding to the signal of polarization 2, and receives the signal of each polarization.

Therefore, each polarization output terminal 42, 43 is adjusted by the polarization demultiplexer 48 so that polarization different from the desired polarization, ie, cross polarization, is reduced.

FIG. 5 shows the signal at the antenna output terminal according to the conventional configuration. The figure shows a case of interleaved arrangement in which polarized waves 1 and 2 are arranged alternately.

(A) in the same figure shows the signal output from the output terminal 42, which shows vertical polarization, and in addition to the desired polarization I, a signal of polarization 2, which is cross polarization, is also output. Put it away. The same figure (B
) is the signal output from the output terminal 43, which indicates horizontal polarization, and similarly, in addition to the desired polarization 2, the cross-polarization polarization 1
is output. At this time, since the frequency of the cross-polarized wave is close to the desired polarized wave, a cross-polarized signal similar to the interference wave will appear as an interference wave within the reception band of the receiver that is trying to receive the desired polarized wave. Mixed.

[Invention or problem to be solved]

However, in the past, cross-polarized signals are mixed in, causing interference with signals of desired polarization and deteriorating communication quality. Therefore, in order to improve the degree of cross-polarization discrimination, it is necessary to make fine adjustments to the rotation angles of the polarization splitter and the reflecting mirror, which has the drawback of being difficult and time-consuming. Also,
When the degree of cross-polarization discrimination deteriorates due to rain or the like, the cross-polarization power becomes relatively large, and this cross-polarization interference has the disadvantage of degrading communication quality.

Furthermore, if you prepare two receivers corresponding to the two polarized waves, or if you try to receive with one receiver, the output terminal of the antenna for either polarized wave will be used depending on the polarized wave of the channel. It was necessary to change the connection. Therefore, there is a problem in that it is necessary to determine which polarization the frequency of the channel to be received is and to switch the output signal of the antenna depending on the polarization.

The present invention was developed in view of the above points, and does not require precise adjustment of the antenna's cross-polarization discrimination, and is not affected by cross-polarization interference even when the cross-polarization discrimination deteriorates due to rain. It is an object of the present invention to provide a polarization sharing receiving device that is capable of maintaining communication quality and is easy to operate.

[Means to solve the problem]

FIG. 1 shows a diagram explaining the principle of the present invention.

In a wireless transmission system that transmits two polarized waves in common, a feeding circuit 11 in an antenna device 10 is configured so that signals of two polarized waves received by the antenna device 10 can be output to two output terminals, respectively. Then, by controlling the phase and amplitude of the output signal from one output terminal of the feeder circuit 11 and combining it with the output signal from the other output terminal of the feeder circuit 11, any one polarization can be suppressed. It has a polarization selection circuit 20 which extracts a desired signal of the other polarization, and a receiver 30 into which the signal of the other polarization extracted from the polarization selection circuit 20 is input. Receive waves.

The polarization selection circuit 20 also includes an amplitude phase control circuit that controls the phase and amplitude of the output signal from one output terminal of the feed circuit 11, and an amplitude phase control circuit that controls the output signal from the other output terminal of the feed circuit 11. A signal that is synthesized with the output signal of , suppresses any one polarized wave, extracts one desired polarized wave, branches the desired one polarized wave into two, and supplies each to the receiver 30 and the amplitude phase control circuit. It consists of a synthetic branch circuit.

Also, the frequency of the polarized signal to be received by the receiver 30,
By setting the difference between the frequency of the polarized wave signal to be detected by the amplitude phase control circuit in advance and adjusting the frequency to select the polarized wave signal to be received, the polarized wave signal to be suppressed can be detected. Frequency adjustment for selection is performed in conjunction.

[Effect]

In the present invention, the feeder circuit 11 branches a signal containing two polarized waves, the polarization selection circuit 20 controls the amplitude phase of one of the branched signals, combines it with the other signal, and further divides this synthesized signal into a signal synthesis branch. The control amount of the amplitude and phase is detected using one signal, and the other branched signal is input to the receiver 30 by the signal synthesis branch circuit, and the frequency of the polarized signal to be received is By setting the difference between the frequency of the signal that detects the amplitude and phase control amount in advance and performing frequency adjustment in conjunction, one polarization can be suppressed and only the signal of the other polarization can be extracted without interference. Since the signal is inputted to the receiver 30 by a simple operation, the signal of the desired polarization can be received without being interfered with by cross-polarization.

〔Example〕

FIG. 2 shows the configuration of an embodiment of the present invention. In this figure, the same parts as in FIG. 1 are given the same reference numerals, and their explanations will be omitted. Reference numeral 20 denotes a polarization selection circuit, which is composed of a combining/branching circuit 21 that combines or branches signals, and an amplitude/phase circuit 22 that compares and controls the amplitude and phase of input signals.

In the figure, the output signal from the antenna device IO, that is, the output signal at the output terminals 12 and 13, is adjusted so that the level of the polarization 1 and polarization 2 signals is approximately equal, as shown in FIG. I'll keep it. As an adjustment method, for example, in a method that uses both vertical and horizontal polarization, the angle of the polarization splitter 11 is set to 45
° Move it.

When trying to receive a polarized wave 1 signal, in order to remove unnecessary polarized wave components, the polarized wave 2 signal output from the antenna output terminal 13 or the polarized wave 2 signal output from the antenna output terminal 12 is used. After being controlled by the amplitude phase control circuit 22 to have equal amplitude and opposite phase, the signal is combined with the output signal of the antenna output terminal 12 by the signal synthesis branch circuit 21, and the signal of polarization 2 is suppressed.

This combined signal is further transferred to the signal combining branch circuit 21.
branched into lineages. One system is input to the receiver 30 as is. The other system is input to the amplitude phase control circuit 22.

The amplitude and phase control circuit 22 detects the residual portion of the polarization 2 signal included in the output signal of the signal synthesis branch circuit 21 . The amplitude and phase of the polarization 1 signal input from the antenna output terminal 12 and the residual portion of the polarization 2 signal are compared. As a result, the amplitude and phase control amounts necessary for suppressing the polarization 2 signal at the output of the signal synthesis branch circuit 21 are obtained,
The amplitude and phase of the output signal of polarization 2 of the antenna output terminal 13 are controlled.

As a result, the signal input to the receiver 30 is suppressed to the polarization 2 signal, and the desired polarization 1 signal can be received without interference from the polarization 2 signal.

Furthermore, when the receiver 30 attempts to receive a signal of polarization 2, the amplitude and phase control circuit 22 detects and controls the residual portion of the signal of polarization 1 in the same manner as described above. As a result, the signal of polarization 2 can be received without being interfered with by polarization 1.

The operation of the amplitude phase control circuit 22 can be realized by using a control method such as an interference compensator generally called a sidelobe canceller (for example, an interference compensator disclosed in Japanese Patent No. 1409006).

That is, polarized wave 2 with respect to polarized wave 1 is similar to the interference wave of the interference compensator.

Also, at this time, it is better to control the amplitude phase control circuit 22 so as to detect and suppress the cross-polarized signal of a channel close to the desired channel of the polarized wave to be received. There are fewer errors due to characteristics, and a greater degree of cross-polarization discrimination can be obtained.

Therefore, as shown in Figure 3, when each channel signal of both polarizations is arranged with a constant frequency difference, the difference between the reception frequency of the receiver and the detection frequency of the amplitude/phase control circuit is If you set it to the frequency difference and make it work together,
Frequency adjustment becomes very easy.

Next, the frequency linkage function will be explained.

The frequency of the polarized signal that interferes with the desired signal is known in advance. Therefore, a frequency difference for suppressing the frequency of a desired signal is given in advance to the frequency adjustment function of the receiver 30 and the frequency adjustment function of the amplitude phase control circuit 22. Next, when the receiver 30 adjusts the frequency to a desired signal, the amplitude and phase control circuit 22 may be adjusted in conjunction with the frequency of the signal to be suppressed. Therefore, as shown in FIG. 3, even if the signals of both polarizations do not have a constant frequency difference, it can be realized.

Such a function can be easily realized by applying the frequency change function for channel selection of a general television tuner, a satellite communication tuner, etc.

Furthermore, when polarization sharing is performed, there are generally cases where orthogonal linear polarization is used and cases where right-handed and left-handed circularly polarized waves are used. The present invention can handle both linearly polarized waves and circularly polarized waves with the same equipment configuration.

In other words, in order to output signals of both polarizations to the antenna output terminal, in the case of linearly polarized waves, the direction of the electric field of each polarized wave must be approximately 4
The power supply circuit 11 is set so as to extract an electric field in a direction forming an angle of 5°.

In the case of circularly polarized waves, it is sufficient to convert them into orthogonal linearly polarized waves at the output of the polarization converter, and then extract the electric field in a direction that is about 45° to the electric field direction, as in the case of linearly polarized waves. Also,
In the case of circularly polarized waves, due to their nature, circularly polarized signals may be mixed in the output, so it is possible to eliminate the polarization converter.

〔Effect of the invention〕

As described above, according to the present invention, there is no need for precise adjustment of the antenna's cross-polarization discrimination, and communication quality is maintained without being affected by cross-polarization interference even when the cross-polarization discrimination deteriorates due to rain. It is possible to maintain the polarization, and the operation is also simplified, making it possible to receive signals of both polarizations with a simple configuration.

In addition, selection and settings such as whether to remove interference waves and set the receiver frequency to target interference waves can be achieved by setting one frequency, which is extremely useful in practice.

[Brief explanation of the drawing]

Fig. 1 is a diagram explaining the principle of the present invention, Fig. 2 is a configuration diagram of an embodiment of the present invention, Fig. 3 is a diagram showing a signal at the antenna output terminal of an embodiment of the present invention, and Fig. 4 is a conventional diagram. FIG. 5 is a diagram showing a signal at an antenna output terminal according to a conventional configuration. lO... Antenna device, 11... Power supply circuit, 20.
... Polarization selection circuit, 21 ... Signal synthesis and demultiplexing circuit, 22
... Amplitude phase control circuit, 30... Receiver. Fig. 1 is a diagram illustrating the principles of the present invention. Fig. 1 is a block diagram of an embodiment of the present invention. Configuration diagram of an example of five wave sharing receivers Fig. 4 (A) Frequency

Claims (3)

[Claims] (1) In a wireless transmission system that transmits two polarized waves in common, a power feeding circuit in the antenna device is configured so that the signals of the two polarized waves received by the antenna device can be output to two output terminals, respectively. and suppressing any one polarization by controlling the phase and amplitude of the output signal from one output terminal of the feeding circuit and combining it with the output signal from the other output terminal of the feeding circuit. a polarization selection circuit that extracts a desired signal of the other polarization, and a receiver into which the signal of the other polarization extracted from the polarization selection circuit is input, and is capable of receiving any polarization. What is claimed is: 1. A dual polarization receiver, characterized in that it is configured to (2) The polarization selection circuit includes an amplitude phase control circuit that controls the phase and amplitude of the output signal from one output terminal of the power supply circuit, and an amplitude phase control circuit that controls the phase and amplitude of the output signal from the other output terminal of the power supply circuit. Combined with the output signal of the control circuit to suppress any one polarized wave to extract a desired one polarized wave, and branch the desired one polarized wave into two and send it to the receiver and the amplitude phase control circuit. Claim 1 comprising a signal combining branch circuit supplying each signal.
The polarization shared receiving device described above. (3) the frequency of the polarized signal to be received by the receiver;
The difference between the frequency of the polarized wave signal to be detected by the amplitude and phase control circuit is set in advance, and the frequency adjustment is performed to select the polarized wave signal to be received, thereby detecting the polarized wave to be suppressed. 3. The dual polarization receiver according to claim 2, wherein frequency adjustment for signal selection is performed in conjunction.