JPH01200732A - Satellite repeating system - Google Patents

Abstract

PURPOSE:To improve system efficiency and reliability by making only the receiving side of a satellite repeater a multi-beam system, making the number of transmitters less than the number of receivers with use of a single-beam system at the transmitting side, and connecting between respective transmitter and receiver with a switch matrix. CONSTITUTION:A signal transmitted from an earth station 1 is convert-amplified into a intermediate frequency which is common by the M number of receivers 4 through a multi-beam antenna 2 and a wave-divider 3. Then, it is connected to the N number of transmitters 5 which is less than M, by MXN switch matrixes 7, is convert-amplified into a frequency for transmitting and is transmitted through a synthesizer 6 and the antenna 2 to the earth station 1. In such a constitution, the earth station 1 inside a service zone #A can receive all the transmitting stations when even it changes a receiving frequency, and the flexibility to the fluctuation of traffic can be secured. Consequently, system efficiency and reliability are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a satellite relay system that efficiently uses a satellite-mounted repeater and achieves high reliability in satellite communications.

(Prior Art) In a satellite communication system, it is advantageous to apply a multi-beam system that provides high antenna gain and allows frequency reuse. An example of the configuration of a conventional multi-beam system is shown in FIG. +a-+c is the service zone irradiated by the multi-beam antenna, and f.

~f6 is the receiving frequency, F1 to F6 are the transmitting frequencies, 1 is the earth station, 2 is the multi-beam antenna for transmitting and receiving, 3 is the demultiplexer, 4 is the receiver, 5 is the transmitter, 6 is the multiplexer, 7 is the MXM switch matrix, 8 indicates a control circuit of the switch matrix. The signal transmitted from the earth station passes through the multi-beam antenna (2) and the branching filter (3), is converted to a common intermediate frequency by the receiver (4), and is amplified.Then, the signal is switched and connected by the M-type switch (7). After that, it is converted and amplified to a transmission frequency by a transmitter 5, and transmitted to the earth station via a multiplexer 6 and a multi-beam antenna 2. FIG. 2 shows an example of the connection state of the switch matrix within one frame.The control circuit of the switch matrix 8 stores this connection state in the circuit, and controls the switch matrix 7 accordingly. The connection status can be changed by commands from the ground. Each earth station in FIG. 1 transmits a burst signal in synchronization with the timing at which its own station's transmission frequency and the target station's reception frequency are connected.

In such a multi-beam system, the gain of the on-board antenna is high, so it is possible to improve transmission capacity and downsize the earth station, and it is possible to reuse frequencies between beams.

(Problem to be solved by the invention) However, it is fine if the traffic is balanced among each beam, but if traffic is concentrated on a specific beam, even if the repeaters for other beams are vacant, the relay It had the disadvantage that it was in a 4S light state because it could not use the equipment. However, if even one beam fails, the system becomes incomplete, so ensuring reliability was a major problem, especially on the lower nine lines, which use high-power amplifiers.

An object of the present invention is to provide a satellite relay system that alleviates the width edge condition of a satellite-mounted repeater and achieves high reliability in the multi-beam system as described above.

(Means for Solving the Problem) The feature of the present invention is to apply a multi-beam method to the uplink and increase the output of the transmitter to increase E I RP (Equival
entisotropicallyRadiated
In addition to applying the single beam system to the downlink where it is possible to improve the effective radiated power (effective radiation power), the number of transmitters N on the single beam side, where traffic congestion is less likely to occur, is smaller than the number of receivers M, and the total The most important feature is that each transmitter/receiver is connected by an MXN switch matrix in order to realize interconnection between earth stations.

(Example) FIG. 3 is a diagram illustrating the present invention in detail.
c is the service zone illuminated by the receiving multi-beam antenna, +, A is the service zone illuminated by the transmitting single beam antenna, f1 to f6 are the receiving frequencies, F1 to F
4 is a transmission frequency, 1 is an earth station, 9 is a multi-beam antenna for reception, 10 is a single beam antenna for transmission, 3 is a demultiplexer, 4 is a receiver, 5 is a transmitter, 6 is a multiplexer, 7' indicates an MxN switch matrix, and 8 indicates a control circuit for the switch matrix. The signal transmitted from the earth station passes through 2 multi-beam antennas and 3 branching filters, is converted to a common intermediate frequency by 4 receivers, and is amplified by a 7'8/11 X N switch matrix. After being switched and connected, it is converted and amplified to the transmission frequency by the transmitter 5, and
The signal is transmitted to the earth station via a plywood and two multi-beam antennas. Figure 4 shows an example of a bow in the connection state of the switch matrix within one frame, and the control circuit of the switch matrix 8 stores this connection state within the circuit, thereby controlling the switch matrix 7'. conduct. The connection status can be changed by commands from the ground.

Each earth station in FIG. 3 transmits a burst signal in synchronization with the timing at which its own station's transmission frequency and the target station's reception frequency are connected. In such a configuration, each receiving earth station can receive from all transmitters by changing the receiving frequency, so a small number of transmitters (6 in Fig. 3) are used for the receivers (6 in Fig. 3). Even with 4 units), sufficient flexibility can be ensured against traffic fluctuations. Furthermore, even if some transmitters fail, reception can be received from all remaining transmitters, which is advantageous in terms of reliability. In general, the receiver operates with low power, so it does not impose a large burden on power consumption, weight, or reliability. It has a great effect in that it can be used efficiently.

(Effects of the Invention) As explained above, the multi-beam system is effective in terms of increasing capacity, downsizing the earth station, and effectively using frequencies, but it has drawbacks in terms of efficient use of repeaters and reliability. had. In the present invention, the multi-beam method is applied only to the receiving side, which is efficient in using repeaters, reliable, and does not impose a large burden.
On the transmitting side, by adopting a single beam system that reduces the number of transmitters while maintaining interconnectivity between each earth station, it is possible to use repeaters more efficiently and improve reliability. This makes it possible to realize a satellite relay system that is highly efficient and reliable as a whole system.

[Brief explanation of the drawing]

Fig. 1 is a system configuration diagram of a conventional satellite communication system using multi-beams, Fig. 2 is an operation diagram of the satellite switch in Fig. 1, Fig. 3 is a system configuration diagram of the present invention, and Fig. 4 is a system configuration diagram of the present invention. FIG. 3 is a diagram showing the connection state within a frame of a switch matrix in FIG. 1...Earth station, 2...Multi-beam antenna for transmission and reception, 3. Brancher, 4. Receiver, 5...Transmitter, 6.Multiplexer, 7...MXM satellite switch, 7' ...B/L X N satellite switch (M>N
), 8... Satellite switch control circuit, 9 - Receiving multi-beam antenna, 10... Transmitting multi-beam antenna, =ll-a~+
-C: Service zone illuminated by the multi-beam antenna +A: Service zone illuminated by the single beam antenna.

Claims (1)

[Claims] In a satellite relay method that uses satellites to relay communications between earth stations within a service area, a receiving antenna that illuminates the service area with multiple beams and a receiving signal on the satellite are placed in a common intermediate frequency band. Equipped with M receivers that convert and amplify signals in the intermediate frequency band, N (M>N) transmitters that convert and amplify signals in the intermediate frequency band into different transmission signals, and a transmitting antenna that illuminates the service area with a single beam. , an intermediate frequency band M×N switch matrix that mutually switches and connects the receiver and transmitter, and control of the switching connection state of the intermediate frequency band switch matrix at a constant frame period based on a monitoring control signal from the ground; A satellite relay system that is equipped with a control circuit that performs this, and is characterized by relaying communications between arbitrary earth stations within a service area.