JPS62219726A - Satellite repeater - Google Patents

Abstract

PURPOSE:To change the relaying capacity of each connection mode in response to a required relay capacity among beams by making the connection of a reception circuit and a transmission circuit different at each split band of a reception RF signal. CONSTITUTION:A switch matrix 3 inputting the output of the 2nd filter means 9 of each reception circuit 1 connects three cross points among 9 points, changes the combination of 3 connection cross points at a prescribed period to connect the combination of all input and output terminals. The output from an output terminal of the circuit 3 is inputted to a transmission circuit 2 of each beam and the input from a signal synthesis/distribution circuit 4 and the input from the switch matrix circuit 3 are combined by a hybrid circuit HYB. Then the RF frequency is subject to frequency conversion by using an output local frequency f0 of a transmission local frequency setting circuit 7 set in matching with the transmission RF frequency decided by the IF signal band in response to a frequency F0, and outputted to each beam. Thus, the relay frequency band of each connection mode is changed in matching with the required transmission capacity.

Description

DETAILED DESCRIPTION OF THE INVENTION (11) Technical field to which the invention pertains The present invention relates to the configuration of a satellite relay device using a multi-beam satellite communication system.

(2) Prior art and its problems Multi-beam satellite communication increases the gain of the satellite antenna and spreads the service area 30 using multiple beams f as shown in Figure 2.
This is a satellite communication system that allows the earth station to be made smaller by covering it with +, fz, f+, and fa, and also enables reuse of the same frequency. Conventionally, in this type of system, all beams were interconnected by installing a switch circuit on the satellite and connecting each beam in a time-sharing manner.

FIG. 3 is a block diagram of a conventional multi-beam satellite relay device. In FIG. 3, 1 is a receiving circuit, 2 is a transmitting circuit, 3 is a switch matrix circuit, 10 is a receiving local frequency oscillation circuit, and 11 is a transmitting local frequency oscillating circuit.

The operation of this conventional multi-beam satellite relay device will be explained. In FIG. 3, the input RF frequency of the receiving circuit l assigned to each beam is frequency-converted by the output frequency of the receiving local frequency oscillation circuit 10, and is all frequency-converted to the same IF frequency. The outputs of each receiving circuit 1 are connected to the input terminals of the switch matrix circuit 3, and the output terminals of the switch matrix circuit 3 are respectively input to different transmitting circuits 2. Within the switch circuit, three appropriate intersections are connected at once. Then, by periodically changing the combination of connection intersections, paths for all input terminals and output terminals are set within one period. The earth station performs time division multiple access using burst signals using the timing when the desired intersection is connected.

As explained above, in the conventional example, it is assumed that a time division multiple access method is used to communicate between all beams, and the signals that can be transmitted are limited to burst signals, which can be realized using a single beam method. Since transmission using continuous wave signals is no longer possible, a separate repeater is required to transmit the continuous wave signals, which poses a problem in that the weight of the repeater increases. In addition, even if the signal transmission capacity using continuous waves and burst waves changes after the satellite is launched, the transmission of continuous wave signals and burst wave signals by each method is determined by the number of transmitter/receiver circuits set before the satellite launch. The problem was that the capacity could not be changed. Therefore, it has been desired to improve the satellite repeater so that it can transmit both burst wave signals and continuous wave signals using the same repeater. As described above, the conventional system has a problem in terms of the versatility of the signal types of usable communication means.

(3) Purpose of the Invention The present invention provides a satellite relay device for multi-beam satellite communications that uses the same transmitting circuit and receiving circuit to realize beam-to-beam connections in a plurality of different modes, thereby transmitting burst wave signals and continuous wave signals. The purpose of the present invention is to provide a satellite relay device for multi-beam satellite communication that can simultaneously relay between arbitrary beams and can change the relay capacity of various connection modes according to the required relay capacity between each beam of each signal format. do.

(4) Structure and operation of the invention The present invention provides a satellite relay device for multi-beam satellite communication that includes a plurality of receiving circuits and a plurality of transmitting circuits, in which a received and received RF signal is supplied to the receiving circuit in order to convert the IF flaw signal frequency. a first frequency setting means for setting a reception local frequency to be transmitted, and a second frequency setting means for setting a transmission local frequency supplied to the transmission circuit for frequency conversion of the IF flaw signal transmission RF multiplied signal; a filter means capable of dividing a single input of an IF frequency band taken out from each of the plurality of receiving circuits into n different frequency bands and outputting the same; a filter means having a plurality of IF input terminals and a plurality of IF output terminals; connecting means for inputting the m-th (m≦n) frequency band output from the receiving circuit to the filter means to each of the transmitting circuits, and The receiving circuit and the transmitting circuit are configured to have different connections for each band, and the first frequency setting means and the second frequency setting means have a configuration in which the transmitting local frequency and the transmitting circuit are connected to each other. The receiving local frequency can be changed, and R is converted into each nm-class IF frequency band of the filter means.
Another feature is that it includes means for changing the F frequency band.

In the present invention, the input signal of the receiving circuit is frequency-divided by the filter means and distributed to a plurality of connection paths, and different arbitrary beam connections can be made simultaneously on the plurality of connection paths. It is also possible to perform communication using time division multiple access using part of the frequency band, while simultaneously performing communication using continuous waves using the remaining band.

Furthermore, even after the satellite is launched, by changing the local frequency of the satellite repeater using a command from the ground, it is possible to change the frequency band distribution of the satellite repeater in accordance with the required transmission capacity of each connection mode.

(5) Examples Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an example of a block configuration of a satellite repeater according to the present invention.

FIG. 4 is an example of signal frequency allocation in a satellite communication system using the satellite repeater of the present invention. In this embodiment, the number of single manual divisions n=2. When the number of types of connection means is 2, one of the two connection means is a signal distribution means that combines the power of multiple input terminals and then distributes the power to multiple output terminals, and the other is a signal distribution means that combines the power of multiple input terminals and then distributes the power to multiple output terminals. An example will be explained in which the switch matrix means has an output terminal and is capable of switching connections between all input terminals and output terminals. Furthermore, in order to demonstrate that it is possible to simultaneously relay burst waves and continuous waves, which is the greatest advantage of the present invention, by using the above-mentioned signal combining and distributing means, SCP C (Single C
SS is operated using the above-mentioned switch matrix method.
- An example of operation using the TDMA method will be explained.

In FIG. 4, signal St is a burst signal using time division multiple access, and signal Sf is a continuous wave signal using frequency division multiple access. In Fig. 4, RFz is the lower limit frequency of the RF frequency band that can be used by a set of receiving paths and transmitting circuits, RF is the upper limit frequency, and RF is the frequency of St and Sf.
, is the boundary frequency of the frequency band used.

FIG. 5 shows an example of the pass frequency band characteristics of a filter circuit which is a characteristic circuit of the present invention. In Figure 5, Ib is IF
It is the center frequency of the frequency band, and the first filter circuit 8
has a passband width FB on the higher frequency side than ■5, and the second filter circuit 9 has a passband width FB on the lower frequency side than ■1.
to have. The frequency band FB is a bandwidth corresponding to the frequency difference between RFu and RFI.

In FIG. 1, the output frequency F0 of the receiving local frequency setting circuit 6 is set in advance to a frequency equal to RFb-1b or RFb+Ib. The frequency setting circuits 5 and 6 have a synthesizer function that receives the output of the reference frequency oscillation circuit 5 as an input. When an RF signal having a spectrum shown in FIG. 4 is input to the receiving circuit 1, it is frequency-converted and becomes an output frequency spectrum of the F frequency band shown in FIG. The output signal of this receiving circuit 1 is transmitted to the first filter means 8 and the second filter means 8.
The first filter means 8 passes only higher frequency signals and blocks lower frequency signals. The second filter means 9 allows only signals on the lower frequency side than (1) to pass through, and blocks signals on the higher frequency side. The output of the receiving circuit 1 for each beam is input to the filter means 8.9 to obtain the output of the first filter means 8 and the output of the second filter means 9 for each beam.

The output of the first filter means 8 of each receiving circuit 1 is input to the signal combining/distributing circuit 4, and the signal combining/distributing circuit 4 combines the power of the inputs from all the receiving circuits 1, and then transmits the same combined signal to each beam. It is distributed to the transmitting circuit 2. On the other hand, each receiving circuit 1
The output of the second filter means 9 is inputted to each input terminal of the switch matrix circuit 3, and the switch matrix circuit 3 connects three of the nine intersections and further connects the combinations of the three connected intersections. It is changed at a constant cycle and all combinations of input terminals and output terminals are connected within one cycle. The output from the output terminal of the switch matrix circuit 3 is input to the transmitting circuit 2 of each beam. In each transmitter circuit 2, the input from the signal synthesis/distribution circuit 4 and the input from the switch matrix circuit 3 are connected to a hybrid circuit (HYB).
), the signal band of the IF band is frequency-converted to an RFF wave number by the output local frequency f0 of the transmitting local frequency setting circuit 7, which is set in advance to match the predetermined transmitting RF frequency according to Fo. output to the beam.

At the earth station, once the frequency bandwidth allocated to the SS-TDMA method and the frequency allocated to the 5cpc method are determined, the local frequency setting circuit of the satellite repeater is set according to the ratio.
A local frequency is set, a burst signal by SS-TDMA is placed on the frequency side lower than the local frequency, and signals are transmitted and received between arbitrary beams at a timing that matches the connection pattern period of the switch circuit. A continuous signal of 5 cpc is transmitted and received on the higher frequency side than the local frequency of . In this embodiment, in order to simplify the explanation, it is assumed that one beam includes one receiving circuit and one transmitting circuit, and that each beam uses the same RF band. However, the effect of the present invention is that Number of transmitter/receiver circuits and RFF
It is not affected by differences in wave numbers.

(6) As described in detail, the present invention enables relaying between arbitrary beams in a plurality of different connection modes using the same transmitting circuit and receiving circuit of a satellite relay device in a multi-beam satellite communication system. Therefore, for example, it is possible to perform continuous wave relaying using frequency division multiple access while performing burst wave relaying using time division multiple access, which has an excellent effect of improving the versatility of the satellite relay device. Furthermore, by making it possible to change the local frequencies of the receiving circuit and transmitting circuit from the ground, the relay frequency band of each connection mode can be changed according to the required transmission capacity without changing the RFF wave number band. Versatility and operability can be further improved.

[Brief Description of the Drawings] Figure 1 is a block configuration diagram of a satellite relay device that is an embodiment of the present invention, Figure 2 is a conceptual diagram of a multi-beam satellite communication system, and Figure 3 is a conventional satellite relay device. FIG. 4 is an RF signal frequency allocation diagram when the present invention is used, and FIG. 5 is an IF pass band characteristic diagram of the filter means of the present invention. DESCRIPTION OF SYMBOLS 1... Receiving circuit, 2... Transmitting circuit, 3... Switch matrix circuit, 4... Signal synthesis distribution circuit, 5... Reference frequency oscillation circuit, 6... Receiving local frequency setting circuit, 7... Transmission local frequency setting circuit, 8, 9... Filter circuit, 10... Receiving local frequency oscillation circuit, 11... Transmitting local frequency oscillation circuit, AMP... Amplifying circuit, HYB... Hybrid circuit, St... Burst wave signal, St
7... Continuous wave signal, RF... Signal transmission bandwidth,
RF...Signal transmission band upper limit frequency, RFI...
Signal transmission band lower limit frequency, RF b...RF band multiplied signal type boundary frequency■,...IF band filter pass band boundary frequency, Fo...Receiving local frequency, fo...
Transmit local frequency.

Claims (2)

[Claims] (1) In a satellite relay device for multi-beam satellite communication including a plurality of receiving circuits and transmitting circuits, a first method for setting a receiving local frequency supplied to the receiving circuit in order to frequency convert a received RF signal to an IF signal. a frequency setting means;
second frequency setting means for setting a transmission local frequency supplied to the transmission circuit for frequency converting the IF signal into a transmission RF signal; and a single IF frequency band extracted from each of the plurality of reception circuits. filter means capable of dividing and outputting an input into n different frequency bands, a plurality of IF input terminals and a plurality of IF output terminals, and an m-th (m
≦n) including k types of connection means for inputting the output of the frequency band to each of the transmitting circuits, and the receiving RF
A satellite relay device characterized in that the connection between the receiving circuit and the transmitting circuit is different for each band into which a signal is divided. (2) The first frequency setting means and the second frequency setting means are capable of changing the transmission local frequency and the reception local frequency, and each of the n types of I of the filter means
2. The satellite relay device according to claim 1, further comprising means for changing the RF frequency band to be converted into the F frequency band.