JPH07105776B2 - Cross polarization 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 cross polarization communication system for communicating with first and second earth stations via satellites by cross polarization, and more particularly to antenna cross polarization of earth stations. Relates to a method of remotely controlling a vehicle.

[0002]

2. Description of the Related Art In satellite communication, for the purpose of effective use of the frequency band of a communication satellite repeater, two orthogonal linearly polarized waves are assigned to each transmitting station (first earth station) to achieve frequency multiplexing. ing. When the polarized wave of the transmitting station antenna and the polarized wave of the communication satellite are deviated, the transmitting station that uses the other polarized wave at the same frequency interferes. Therefore, it is necessary to optimally adjust the cross polarization of the transmitting station. For example, JP-A-61
-46627 discloses a device that obtains good cross polarization characteristics.

FIG. 2 shows a cross polarization adjustment method according to the prior art.
Shown in. The cross-polarized signal strength of the vertically polarized wave and the horizontally polarized wave is measured by the spectrum analyzer 20 through the demultiplexer 12 at the receiving station (second earth station). In the transmitting station, the power feeding unit 1 of the antenna is rotated by an electric or manual driver 2'to adjust the cross polarization of the transmitted wave to be optimum. In the adjustment, the measurer at the receiving station
The signal intensities of the vertically and horizontally polarized waves are read by the spectrum analyzer 20, respectively, so that the polarized waves assigned to the transmitting station are maximized and the cross polarized waves thereof are minimized.
Through the telephone line 21, the rotation direction and the stop position of the power feeding unit 3 of the transmitting station are designated.

[0004]

In the prior art, since the propagation delay of the satellite line to be measured is very large with respect to the telephone line which is the communication line between the measuring persons, the judgment and transmission of the measured value are carried out. There is a problem that the rotation of the power supply unit of the station does not match. In order to avoid this, it is necessary to adjust the rotation of the power feeding section of the transmitting station at a waiting time interval longer than the propagation delay of the satellite line, and it takes time to adjust the cross polarization.

An object of the present invention is to eliminate the above-mentioned problems and to provide a cross polarization communication system capable of accurately adjusting two polarization components of cross polarization.

Another object of the present invention is to prevent cross polarization.
An object of the present invention is to provide a cross polarization communication system that enables adjustment of two polarization components in a short time.

Another object of the present invention is to provide a cross polarization communication system capable of automatically adjusting two polarization components of cross polarization.

[0008]

According to the present invention, there is provided a cross-polarization communication system for communicating with first and second earth stations by means of cross-polarization via a satellite. The station includes a first antenna feeding unit that feeds power to the first antenna, a motor that rotates the first antenna feeding unit, and a rotation angle detector that detects a rotation angle of the first antenna feeding unit. And a first encoding the detected rotation angle
And a first transmitter for transmitting the coded rotation angle from the first antenna as a first cross-polarized wave via the first antenna feeding unit, The second earth station receives a second antenna power feeding unit that feeds power to the second antenna and the first cross-polarized wave from the first antenna via the first antenna power feeding unit, The first
Demultiplexer for demultiplexing the cross polarization of two polarization components orthogonal to each other, a switcher for switching and outputting the two polarization components, and a signal strength of the two polarization components output for switching At the same time, the receiver and decoder for decoding the encoded rotation angles of the two polarization components switched and output, and the two polarization components from the signal strength of the two polarization components and the decoded rotation angle. A cross polarization determiner for generating a rotation control signal for controlling the rotation angle of the motor so as to maximize the signal strength of one of the wave components and minimize the other. Wave communication system is obtained.

Further, according to the present invention, the second earth station may further include an encoder for encoding the rotation control signal, and the encoded rotation control signal via the second antenna feeding unit. A transmitter for transmitting as a second cross-polarized wave from two antennas, wherein the first earth station is configured to transmit the second cross-polarized wave from the first antenna to the first antenna feeding unit. A receiving decoder for receiving the encoded rotation control signal and decoding the encoded rotation control signal, the detected rotation angle from the rotation angle detector, and the decoded rotation control signal based on the intersection. A means for controlling the rotation angle of the motor so that the signal intensity of one of the two polarization components in the polarization determiner becomes maximum and the other becomes minimum. The cross polarization communication system described can be obtained.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows an embodiment of the present invention. In FIG. 1, a drive motor 2 is attached to a power feeding unit 1 of an antenna of a transmitting station. When the motor 2 drives the power supply unit 1, the rotation angle detector 3 detects the rotational position of the power supply unit 1, that is, the polarization angle. Rotation angle detector 3
Is encoded by the encoder 4 and transmitted through the transmitter 5 to the receiving station via the satellite.

In order to receive the rotation control signal of the power feeding section 1 from the receiving station, the transmitting station is provided with a demultiplexer 6, a combiner 7, a receiver 8 and a decoder 9. The demultiplexer 6 has two orthogonal linearly polarized wave outputs, and the outputs are combined by the combiner 7. The decoder 9 is for decoding the encoded rotation control signal from the receiving station. The decoding result is compared with the output of the rotation angle detector 3 by the comparator 10. The comparator 10 compares the rotation control signal from the receiving station with the rotation position of the power feeding unit 1 to determine whether the motor 2 should be driven in any rotation direction or should be stopped.

In the receiving station, the output from the power feeding portion 11 of the antenna is demultiplexed by the demultiplexer 12 into two vertically polarized waves, which are input to the switch 13. The switch 13 selects one of the two polarizations and the receiver 14 measures its signal strength. In addition, the decoder 15
At, the rotational position encoded and transmitted by the transmitting station is decoded, and the cross polarization determiner 16 takes in the signal strength and the rotational position corresponding thereto. The cross polarization determiner 16 is a switch 1
Since the switching of the reception polarized wave is controlled for 3, it is possible to determine which of the polarized waves the captured signal strength and the rotation position are.

In the cross polarization determiner 16, the polarization assigned to the transmitting station is the strongest and the cross polarization is the minimum based on the signal strength, the rotation position, and the polarization type associated with each other as described above. The rotation stop position of the power feeding unit 1 is controlled for the transmitting station. At the time of control, the encoder 17 encodes the rotation control signal and transmits it to the transmitting station through the transmitter 18.

Polarization diversity reception is possible by providing the combiner 8 in the receiving device of the transmitting station, and even if the received polarized wave changes due to the rotation of the power feeding unit 1, the rotation control signal from the receiving station is received. Never lose track of your transmitted waves.

[0015]

According to the present invention, since the polarization angle at the transmitting station as the first earth station is encoded and transmitted, the cross polarization signal strength at the receiving station as the second earth station is obtained. And the polarization angle of the transmitting station can be made to correspond one to one. Therefore, even if the propagation delay of the satellite line is involved, the determination of the optimum value of the cross polarization characteristics at the receiving station and the stop position of the power supply unit drive motor at the transmitting station do not become inconsistent. In addition, since it is possible to make one-to-one correspondence between the cross polarization signal strength and the polarization angle of the transmitting station, there is no need to provide a waiting time longer than the propagation delay time of the satellite line. It is possible to continuously instruct the rotation control signal of the power feeding unit, and there is an effect that the adjustment time of cross polarization can be shortened as compared with the related art.

[Brief description of drawings]

FIG. 1 is a block diagram of a cross polarization communication system according to an embodiment of the present invention.

FIG. 2 is a block diagram of a conventional cross polarization communication system.

[Explanation of symbols]

 1 Feeder 2 Motor 2'Drive 3 Rotation Angle Detector 4 Encoder 5 Transmitter 6 Splitter 7 Synthesizer 8 Receiver 9 Decoder 10 Comparator 11 Feeder 12 Splitter 13 Switcher 14 Receiver 15 Decoder 16 Cross polarization determiner 17 Encoder 18 Transmitter 20 Spectrum analyzer 21 Telephone line

Claims (2)

[Claims] 1. A cross polarization communication system for performing cross polarization communication between a first earth station and a second earth station via a satellite, wherein the first earth station feeds power to a first antenna. A first antenna feeding part, a motor for rotating the first antenna feeding part, a rotation angle detector for detecting a rotation angle of the first antenna feeding part, and a detected rotation angle. And a first transmitter for transmitting the encoded rotation angle from the first antenna as the first cross polarization through the first antenna feeding unit. The second earth station supplies the first cross-polarized wave to the first antenna power supply unit that supplies power to the second antenna.
From the above antenna through the first antenna feeding unit, and a demultiplexer for demultiplexing the first cross polarization into two polarization components orthogonal to each other, and switching output of the two polarization components And a receiver / decoder that outputs the signal strengths of the two polarization components that are switched and output, and that decodes the encoded rotation angles of the two polarization components that are switched and output,
From the signal strengths of the two polarization components and the decoded rotation angle, the rotation angle of the motor is controlled so as to maximize the signal strength of one of the two polarization components and minimize the other. And a cross polarization judging device for generating a rotation control signal. 2. The second earth station includes an encoder for encoding the rotation control signal, and an encoded rotation control signal from the second antenna via the second antenna feeding unit. And a transmitter transmitting as two cross-polarized waves, wherein the first earth station receives the second cross-polarized wave from the first antenna via the first antenna feeding unit. A receiving decoder that decodes the encoded rotation control signal, the detected rotation angle from the rotation angle detector, and the decoded rotation control signal based on the decoded rotation control signal. The cross-polarized wave according to claim 1, further comprising: a unit that controls a rotation angle of the motor so that a signal strength of one of the two polarization components is maximized and the other is minimized. Communication method.