JP2000183798A - Satellite communication earth station - Google Patents

Abstract

PROBLEM TO BE SOLVED: To change a satellite of a communication destination with a simple work by having only to select a switch so as to change a satellite in use. SOLUTION: A satellite communication earth station 10 includes a switch SW1, and the switch SW1 is placed between an indoor unit IDU 26 (32) and a terminal station 28. In the case of using a satellite 16, the switch SW1 is thrown to the position of a transmitter-receiver 12. That is, the transmitter- receiver 12 is used for transmission/reception with the satellite 16. On the other hand, in the case of using a satellite 18, the switch SW1 is thrown to the position of a transmitter-receiver 14. That is, the transmitter-receiver 14 is used for transmission/reception with the satellite 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a satellite communication earth station, and particularly to, for example, JCSAT-3 and SUPERBIRD.
The present invention relates to a satellite communication earth station applied to satellite communication using -C.

[0002]

2. Description of the Related Art When performing satellite communication within an area covered by one satellite, one satellite used by a satellite communication earth station is sufficient. On the other hand, when a plurality of satellites having different frequencies are used to expand the communication area, the same number of satellite communication earth stations are required. However, since there is a time difference between the areas covered by the respective satellites, it is possible to use only one satellite earth station if a plurality of satellites are not used at the same time. That is, by changing the setting according to the satellite to be used, one satellite communication earth station can communicate with a plurality of satellites.

[0003]

In this prior art, in order to switch the satellite to be used, it is necessary to change not only the frequency and the transmission power but also the direction of the antenna having a diameter of 1.8 m to 2.4 m. The switching operation is not easy. Therefore, a main object of the present invention is to provide a satellite communication earth station capable of changing a communication destination satellite with a simple operation.

[0004]

According to a first aspect of the present invention, there are provided a plurality of antennas respectively corresponding to a plurality of satellites, a plurality of processing means respectively corresponding to the plurality of antennas and processing communication signals, and input and output of communication signals. The satellite communication earth station includes one input / output unit for performing the operation and a connection unit for connecting the input / output unit to any one of the plurality of processing units.

According to a second aspect of the present invention, there are provided a plurality of antennas respectively corresponding to a plurality of satellites, high frequency processing means respectively corresponding to the plurality of antennas and processing a high frequency signal of a communication signal, and one input / output unit for inputting / outputting the communication signal Output means, one frequency conversion means provided between the plurality of high frequency processing means and the input / output means and performing frequency conversion between a high frequency and an intermediate frequency, and between the plurality of high frequency processing means and the frequency conversion means And a connection means for connecting any one of the plurality of high-frequency processing means to the frequency conversion means.

[0006]

An antenna is connected to each of the satellite earth stations, and the antenna is provided corresponding to each of the plurality of satellites. The plurality of processing units process communication signals corresponding to the respective antennas. One input / output unit for inputting / outputting a communication signal is provided, and the connection unit connects the input / output unit and any one of the plurality of processing units.

[0007] In one aspect of the present invention, the processing means includes a high frequency processing means and a frequency conversion means. The high frequency processing means processes a high frequency signal transmitted to and received from a corresponding satellite, and the frequency conversion means performs frequency conversion between a high frequency and an intermediate frequency. An antenna is connected to each of the satellite communication earth stations, and the antenna is provided corresponding to each of the plurality of satellites. The plurality of high frequency processing units process the high frequency of the communication signal corresponding to each antenna. One input / output unit for inputting / outputting communication data is provided.
The frequency conversion means is provided between the plurality of high frequency processing means and the input / output means, and performs frequency conversion between a high frequency and an intermediate frequency. The connection means is provided between the plurality of high-frequency processing means and the frequency conversion means, and connects any one of the plurality of high-frequency processing means to the frequency conversion means.

[0008] In another aspect of the invention, detection means for detecting the level of a reference signal output from a satellite is provided,
The comparing means compares the detection level with a reference level. The output means outputs a signal corresponding to the comparison result. In another embodiment of the invention, the output means includes a display means, and the display means displays the high frequency processing means in use.

[0009] In another embodiment of the invention, the reference signal is a beacon signal.

[0010]

According to the present invention, any one of the plurality of processing means is simply connected to the input / output means, so that the communication destination satellite can be changed with a simple operation. According to another aspect of the present invention, any one of the plurality of high frequency processing units is simply connected to the frequency conversion unit, so that the communication destination satellite can be changed with a simple operation.

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a satellite communication earth station 10 of this embodiment includes transmitting and receiving devices 12 and 14. The transmitting and receiving devices 12 and 14 are provided with antennas 20 and 22 so as to be directed to the corresponding satellites 16 and 18. For example, satellite 16 is JCSAT-3 and satellite 18 is S
UPERBIRD-C is a geostationary satellite with a circular orbit on the equator and a period equal to the rotation of the earth.

The antenna 20 has an outdoor unit (O).
DU) 24, and an indoor unit (IDU) 26 is connected to the ODU 24. The IDU 26 is connected to the terminal device 28 via the switch SW1. In this embodiment, a switch “SWL350A” manufactured by BLACK BOX can be used as the switch SW1. In this case, the interface used for the connection is an interface “RS-449” manufactured by the company.

An ODU 30 is connected to the antenna 22, and an IDU 32 is connected to the ODU 30. IDU
32 is also connected to the terminal device 28 via the switch SW1. The switch SW1 is switched according to the satellite 16 or 18 used by a control device (not shown). The transmitting and receiving devices 12 and 14 have different frequencies,
Since the transmission power for operation is also different, data on the frequency and the transmission power is set in the terminal device 28 in advance on an operation panel (not shown) provided in the IDU 26.

The ODU 24 (30) and the IDU 26 (3
To explain in detail 2), as shown in FIG.
The DU 24 (30) includes a duplexer 41, a low-noise amplifier 44, a receiving frequency converter (D / C) 46, a transmitting frequency converter (U / C) 52, a large power amplifier 54, and the like. The IDU 26 (32) is provided with a receiving circuit 40 including a demodulator and a transmitting circuit 42 including a modulator.

A transmission signal from the satellite 16 or 18 is received by the antenna 20 or 22, and the received transmission signal (received signal) is provided to the duplexer 41. The received signal is amplified by the low noise amplifier 44 via the duplexer 41. The received signal (high-frequency signal) output from the low-noise amplifier 44 is converted into an intermediate frequency signal by the D / C 46 and demodulated by the receiving circuit 40. The demodulated received signal (baseband signal) is provided to the terminal device 28. The transmission signal (baseband signal) is modulated by the transmission circuit 42. The modulated transmission signal (intermediate frequency signal) is U /
The signal is converted into a high-frequency signal by C52, amplified by the high power amplifier 54, and supplied to the duplexer 41.

According to this embodiment, the switch SW1 is set to I
It is provided between the DU 26 (32) and the terminal device 28, and the satellite to be used can be changed only by switching the switch SW1, so that the communication destination satellite can be changed with a simple operation. In addition, since the terminal device 28 can be commonly used, the cost can be reduced. In another embodiment of the satellite communication earth station 10 shown in FIG.
W1 is provided between the ODU 24 (30) and the IDU 26, and the beacon signal level detectors 60 and 66, the level comparison / determination devices 62 and 68, and the reference voltage generator 64
1 and FIG.
Since it is the same as the embodiment, the duplicated description will be omitted. In this satellite communication earth station 10, the transmitting / receiving device 14 shown in FIG.
Can be omitted. That is, since the ODU 24 is provided integrally with the antenna 20 and the ODU 30 is provided integrally with the antenna 22, they cannot be used in common. However, since the IDU 26 is installed indoors, they can be used in common. OD
Since a high-frequency signal is exchanged between U24 and U30 and IDU 26, a coaxial cable is used for connection. For this reason, the switch SW1 is required to have a high isolation and a low band. That is, for example, O
If a high-frequency signal to be input to the DU 24 leaks to the ODU 30, a signal to be transmitted to the satellite 16 is erroneously emitted to the satellite 18. Then, nothing is transmitted to the other satellite communication earth station using the satellite 16. Further, if the isolation is small even if the switching of the switch SW1 is not mistaken, the high frequency signal to be input to the ODU 24 is
0, transmitted from the satellite communication earth station 10, and transmitted to the satellite 1
This signal becomes noise to the satellite communication earth station of the other party that uses 8 and causes great damage. For this reason, a switch having excellent isolation is required. In addition,
As the switch SW1 of this embodiment, a switch “HCS2-111-F” manufactured by Hirose Electric Co., Ltd. can be used.

The beacon signal output from the satellite 16 or 18 is detected by the beacon signal level detectors 60 and 66 via the switch SW1. The beacon signal level detection device 60 detects the level of the input beacon signal. The detection signal (detection level) of the beacon signal level detection device 60 is given to the level comparison / judgment device 62, and the reference voltage from the reference voltage generation device 64 is also given to the level comparison / judgment device 62. The level comparison determination device 62 compares the detection signal from the beacon signal level detection device 60 with the reference voltage from the reference voltage generation device 64 to determine whether the currently received signal is an output signal from the satellite 16. . The determination result of the level comparison determination device 62 is given to the display device 72.

The beacon signal level detector 66 detects an output signal from the satellite 16 or 18 via the switch SW1, and detects a level of a beacon signal included in the output signal. The level comparison / judgment device 68 includes a detection signal from the beacon signal level detection device 66 and the reference voltage generation device 7.
By comparing with the reference voltage from 0, it is determined whether or not the currently received signal is an output signal from the satellite 18. The determination result from the level comparison determination device 68 is given to the display device 72.

The display device 72 includes a level comparison / determination device 62
And the transmitting and receiving device 12
And 14 are detected and used and displayed so that the transmitting / receiving device 12 or 14 used can be identified. That is, the display device 72 is provided with two LEDs 72a and 72b, and the LED 72a or 72b corresponding to the transmitting / receiving device 12 or 14 being used.
b is turned on. Therefore, by monitoring the display device 72, it can be determined whether or not the switch SW1 is correctly switched.

According to another embodiment, switch SW1 is set to O
Since it is provided between the DU 24 (30) and the IDU 26, the IDU 32 can be omitted. That is,
Further, costs can be reduced. In addition, the beacon signal included in the output signals from the satellites 16 and 18 is detected, and the display device 72 displays which of the transmitting / receiving devices 12 and 14 is being used based on the level of the beacon signal. , Switch SW1 can be accurately switched.

In these embodiments, two communication satellite earth stations 12 and 14 have been described. However, three or more communication satellite earth stations may be provided. Further, a personal computer is connected to the terminal device 28, and by detecting the output signal of the terminal device 28, the intensity of the output signal from the satellite 16 or 18 is detected. The drive can be controlled to fine tune the orientation and elevation of the antennas 20 and 22.

Further, when a beacon signal is detected as in the other embodiments, the output signals of the level comparison / determination devices 62 and 68 are detected by a personal computer instead of the output signal of the terminal device 28. Satellite 1
The strength of the output signals from 6 and 18 may be detected, and the antenna driving device may be controlled to finely adjust the directions and elevation angles of the antennas 20 and 22.

Further, in another embodiment, the beacon signal is detected, but a telemetry signal may be detected instead of the beacon signal.

[Brief description of the drawings]

FIG. 1 is an illustrative view showing one embodiment of the present invention;

FIG. 2 is an illustrative view showing an IDU shown in FIG. 1 embodiment;

FIG. 3 is an illustrative view showing another embodiment of the present invention;

[Explanation of symbols]

 10 Satellite earth station 12, 14 Transmitter / receiver 24, 30 ODU 26, 32 IDU 28 Terminal device 60, 66 Beacon signal level detector 62, 68 Level comparison / determination device 64, 70 Reference voltage Generator 72… Display device

Claims (6)

[Claims] 1. A plurality of antennas respectively corresponding to a plurality of satellites, a plurality of processing means respectively corresponding to the plurality of antennas and processing a communication signal, one input / output means for inputting / outputting the communication signal, and A satellite communication earth station comprising a connection means for connecting said input / output means to any one of said plurality of processing means. 2. The apparatus according to claim 1, wherein said processing means includes a high-frequency processing means for processing a high-frequency signal transmitted to and received from the corresponding satellite, and a frequency conversion means for performing frequency conversion between a high frequency and an intermediate frequency. 2. The satellite communication earth station according to 1. 3. A plurality of antennas respectively corresponding to a plurality of satellites, high frequency processing means respectively corresponding to the plurality of antennas and processing a high frequency signal of a communication signal, and one input / output means for inputting / outputting the communication signal A frequency conversion unit provided between the plurality of high frequency processing units and the input / output unit and configured to perform frequency conversion between a high frequency and an intermediate frequency; and the plurality of high frequency processing units and the frequency conversion unit. A satellite communication earth station comprising: a connection unit provided between the plurality of high-frequency processing units and the frequency conversion unit. 4. A detecting means for detecting a level of a reference signal output from the satellite, a comparing means for comparing a detection level of the detecting means with a reference level, and an output means for outputting a signal corresponding to the comparison result. 4. The method of claim 3, further comprising:
Satellite earth station as described. 5. The satellite communication earth station according to claim 4, wherein said output means includes display means for displaying said high-frequency processing means in use. 6. A satellite communication earth station according to claim 4, wherein said reference signal is a beacon signal.