JPH0724390B2 - Multi-satellite satellite communication Earth station equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a multi-satellite communication system, and more particularly to a satellite communication system (satellite hopping system) that is operated by instantaneously switching a satellite used for relaying from a plurality of satellites. Called)).

(Prior Art) Communication satellites in geostationary orbit are placed at intervals of about 36,000 km above the equator to avoid interference. From this, even if multiple communication satellites using the same frequency band have different directions from the earth station, multiple earth satellites using the conventional single-beam antenna (conventional antenna with a single transmitting and receiving direction) It was not possible to instantaneously switch the satellites used for relaying from the satellites to operate (satellite hopping). FIG. 1 is a diagram showing a satellite communication earth station apparatus using a conventional single beam antenna set.
11 is satellite a, 12 is satellite b, 13 is the main reflector of the antenna, 14
Is the sub-reflector of the antenna, 15 is the primary radiator of the antenna, 16
Is a transmission / reception demultiplexer, 17 is a transmitter, 18 is a receiver, 19 is a transmission signal input, and 110 is a reception signal output. In the conventional satellite communication earth station, when changing the satellite used for relay, it is necessary to change the direction of the antenna, so that there is a drawback that communication is temporarily interrupted. Therefore, if it is not possible to build a large capacity satellite communication system that exceeds the line capacity of one communication satellite, and if all communication lines of the satellite in use are communicating, the earth station will increase the line setting amount. The disadvantage was that it could not be done when it was needed. Further, when the satellite in use breaks down, there is a drawback that communication is temporarily interrupted until the antenna is directed to another satellite.

On the other hand, conventionally, an earth station has a plurality of single beam antennas, a specific satellite is instantly selected by selecting an antenna, and satellites used for relay are instantaneously switched from a plurality of satellites to operate (satellite hopping). There was a way. FIG. 2 is a diagram showing a first example of a conventional satellite communication earth station apparatus using a plurality of single beam antennas,
21 is satellite a, 22 is satellite b, 23 and 24 are antenna main reflectors, 25 and 26 are antenna sub-reflectors, 27 and 28 are antenna primary radiators, 29 and 210 are transmitter / receiver demultiplexers, 211 Is the transmitter, 21
2 is a receiver, 213 is a switch for switching the transmitting antenna (switching in high frequency band, intermediate frequency band, or baseband), 214 is a switch for switching receiving antenna (switching in high frequency band, intermediate frequency band, or baseband band) , 215 is a transmission signal input, and 216 is a reception signal output. In this example, a signal of one channel is input and output for both transmission and reception, the antenna to be used is switched by switching the switch, and communication is performed by switching the satellite to be used independently for transmission and reception without interruption of communication. Although this example shows the case where the number of satellites is 2, generally n (n =
Used in the case of 2,3,4 ...) satellites. FIG. 3 is a diagram showing a second example of a conventional satellite communication earth station apparatus using a plurality of single beam antennas, in which 31 is satellite a, 32 is satellite b, 33 and 34 are main reflecting mirrors of the antenna, 35 and 36 are sub-reflectors of the antenna, 37 and 38 are primary radiators of the antenna, and 39 and 31.
0 is a transmission / reception demultiplexer, 311 is a transmitter, 312 is a receiver, 313 is a switch for switching the transmission antenna (high-frequency band, intermediate frequency band, or baseband band), 314 is a switch for switching the reception antenna (high-frequency band) , 315 is a transmission channel 1 signal input, 316 is a transmission channel 2 signal input, 317 is a reception channel 1 signal output, and 318 is a reception channel 2 signal output. In this example, signals for multiple channels are input and output for both transmission and reception, the antennas used between the signal channels are switched by switching the switch, and communication is continuous for each channel, and satellites used independently for transmission and reception. To switch between and communicate. This example shows the case where the number of satellites is 2 and the number of transmitting / receiving channels is 2, but generally n (n = 2,3,4, ...)
This is used for the case of m satellites (m = 2,3,4, ...) Number of transmitting / receiving channels.

(Problems to be Solved by the Invention) In the example of the satellite communication earth station using a plurality of conventional single beam antennas shown in FIGS. 2 and 3, a plurality of antennas are used, and thus a wide installation place is required. Another disadvantage is that the cost of the antenna increases.

An object of the present invention is to prevent a satellite communication earth station apparatus using a conventional single beam antenna from constructing a large capacity satellite communication system exceeding the line capacity of a single communication satellite. When the line is communicating, the disadvantages that the earth station in the system cannot further increase the line setting amount and the problem that the communication is temporarily interrupted when the satellite in use breaks down, and what is the satellite in use? To provide an earth station device capable of transmitting and receiving to and from another communication satellite having a free line at any time and increasing the line setting amount without interruption of communication, and to provide another satellite when the satellite in use breaks down. An object of the present invention is to provide an earth station device capable of continuing communication without interruption using. In addition, in the conventional earth station device using a plurality of single beam antennas that enables this, the disadvantage that the device is large and expensive is solved, and the earth station instantly selects a specific satellite from a plurality of satellites. , It is to provide a small and inexpensive earth station device capable of instantaneously switching and operating satellites used for relaying.

(Means for Solving the Problems) The present invention relates to a satellite communication system composed of a plurality of satellites and a plurality of earth stations which perform multiplex communication, and an earth station having a single beam antenna instantaneously switches the satellites for communication. What could not be done, or what the earth station had multiple single beam antennas for instant satellite switching to communicate, the earth station instantly switched multiple satellites In order to perform communication, it has a multi-beam antenna (antenna with multiple transmission / reception directions by transmitting / receiving multiple beams) and by selecting that beam direction, a specific satellite can be selected instantaneously. The most main feature. Conventional technology means that when a satellite communication earth station changes the satellite used for communication,
In the present invention, a plurality of antennas used for communication are switched by switching the satellites by changing the direction of the antenna over time, or a plurality of antennas used for communication are switched. Instantly select a specific satellite from the satellites and use it for relay,
The difference is that it is a small and inexpensive earth station device that can communicate without loss of information.

(Embodiment) FIG. 4 is a view showing a first embodiment of the present invention, in which 41 is a satellite a, 42 is a satellite b, 43 is a main reflecting mirror of an antenna, 44 is a sub-reflecting mirror of an antenna, 45, 46 is the primary radiator of the antenna, 47,
48 is a transmission / reception demultiplexer, 49 is a transmitter, 410 is a receiver, 411 is a switch for switching the primary radiator used for transmission (switching between high frequency band, intermediate frequency band, or baseband band), 412 is used for reception A switch for switching the primary radiator (switching in a high frequency band, an intermediate frequency band, or a base band band), 413 is a transmission signal input, and 414 is a reception signal output. In this embodiment, a signal of one channel is input and output for both transmission and reception, the primary radiator to be used is switched by switching the switch, and the satellite to be used independently for transmission and reception is switched without any interruption of communication. I do. Although this embodiment shows the case where the number of satellites is 2,
The present invention is not limited to this case, but is generally applied to the case of n (n = 2,3,4, ...) Satellites.

FIG. 5 is a diagram showing a second embodiment of the present invention, in which 51 is a satellite a, 52 is a satellite b, 53 is a main reflector of an antenna, 54 is a sub-reflector of an antenna, and 55 and 56 are antennas. Primary radiator, 57,
58 is a transmission / reception demultiplexer, 59 is a transmitter, 510 is a receiver, 511 is a switch for switching the primary radiator used for transmission (switching between high frequency band, intermediate frequency band, or baseband band), 512 is used for reception Switch for switching the primary radiator (high-frequency band, intermediate frequency band, or baseband band), 513 for transmitting channel 1 signal input, 5
Reference numeral 14 is a transmission channel 2 signal input, 515 is a reception channel 1 signal output, and 516 is a reception channel 2 signal output.
In this embodiment, one of the satellites a and b is selected independently for transmission and reception, and the satellites to be used are switched for communication. In this embodiment, signals of multiple channels are input and output for both transmission and reception, and by switching the switches, the primary radiators used between the signal channels are exchanged, and transmission and reception are continued with each channel.
Communication is performed by switching the satellites used independently for reception. Although the present embodiment shows the case where the number of satellites is 2 and the number of transmission / reception channels is 2, the present invention is not limited to this case, and generally n (n = 2, 3, 4, ...) This applies to the case of m satellites (m = 2,3,4, ...) Number of transmitting / receiving channels.

The effect of the embodiment shown in FIG. 4 and FIG. 5 is that the conventional earth station uses a single beam antenna, so that the satellite communication system operated by using a plurality of satellites for relaying can transmit and receive without interruption of communication. It was impossible to change the satellite that performs the transmission, or it was large and expensive because multiple single beam antennas were used to change the satellite that transmits and receives without interruption of communication. In this case, the multiple beam directions of the multi-beam antenna are always tracking each of the multiple satellites in the system, so that the satellites that transmit and receive can be changed or the number of satellites that transmit and receive can be increased or decreased without interruption of communication. Moreover, there is an advantage that it can be realized by an inexpensive device.

In this embodiment, a torus antenna, a bifocal antenna, or the like can be used as the multi-beam antenna. Further, as the transmitter and the receiver, those having a switching function of a transmission frequency and a reception frequency and capable of transponder hopping can be used.

(Effects of the Invention) As described above, according to the present invention, a multi-beam antenna is used for an earth station, and each beam direction individually tracks a plurality of communication satellites in the system, thereby transmitting and receiving without interruption of communication. There is an advantage that it is possible to change the satellites that perform the above or increase or decrease the number of satellites that perform the transmission and reception. In addition, even if all lines of a specific satellite are in communication, there is an advantage that the earth station in communication can increase the line setting amount by using a satellite with another idle line in the system for relaying. is there.
Further, there is an advantage that such a satellite communication earth station apparatus can be constructed in a small size and at a low cost. As a result, there is an advantage that it is possible to construct a satellite communication system having a large communication capacity, as compared with a satellite communication system using an earth station device using a conventional set of single beam antennas. In addition, if the satellite in use breaks down, there is an advantage that communication can be continued without interruption using another satellite. Further, as compared with the conventional earth station device using a plurality of single beam antennas, it is possible to instantly select a specific satellite from a plurality of satellites and perform communication without loss of information by a small and inexpensive earth station device. There is an advantage.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a satellite communication earth station apparatus using a conventional set of single beam antennas, and FIG. 2 is a first example of a satellite communication earth station apparatus performing satellite hopping using a plurality of conventional single beam antennas. Figure showing an example, third
FIG. 4 is a diagram showing a second example of a satellite communication earth station apparatus that performs satellite hopping using a plurality of conventional single beam antennas, and FIG. 4 is a satellite communication that performs satellite hopping using the multi-beam antenna proposed by the present invention. FIG. 5 is a diagram showing a first embodiment of the earth station device, and FIG. 5 is a diagram showing a second embodiment of the satellite communication earth station device for performing satellite hopping using the multi-beam antenna proposed in the present invention. 11 …… satellite a 12 …… satellite b 13 …… antenna main reflector 14 …… antenna subreflector 15 …… antenna primary radiator 16 …… transmission / reception duplexer 17 …… transmitter 18 …… reception Unit 19 …… Sending signal input 110 …… Reception signal output 21 …… Satellite a 22 …… Satellite b 23,24 …… Main antenna reflecting mirror 25,26 …… Antenna subreflecting mirror 27,28 …… Antenna Primary radiator 29, 210 …… Transmit / receive demultiplexer 211 …… Transmitter 212 …… Receiver 213 …… Switch for switching transmitting antenna 214 …… Switch for switching receiving antenna 215 …… Transmission signal input 216 …… Reception signal output 31 …… satellite a 32 …… satellite b 33,34 …… antenna main reflector 35,36 …… antenna subreflector 37,38 …… antenna primary radiator 39,310 …… transceiver duplexer 311 …… Transmitter 312 …… Receiver 313 …… Switch to switch the transmitting antenna 314 …… Switch the receiving antenna Switch 315 …… Transmit channel 1 signal input 316 …… Send channel 2 signal input 317 …… Receive channel 1 signal input 318 …… Receive channel 2 signal input 41 …… Satellite a 42 …… Satellite b 43 …… Main antenna Reflector 44 …… Antenna subreflector 45,46 …… Antenna primary radiator 47,48 …… Transmit / receive demultiplexer 49 …… Transmitter 410 …… Receiver 411 …… Switch the primary radiator used for transmission Switch 412 …… Switch for switching the primary radiator used for reception 413 …… Transmission signal input 414 …… Reception signal output 51 …… Satellite a 52 …… Satellite b 53 …… Main reflector of antenna 54 …… Secondary reflection of antenna Mirror 55, 56 …… Primary antenna radiator 57, 58 …… Transmit / receive demultiplexer 59 …… Transmitter 510 …… Receiver 511 …… Switch to switch the primary radiator used for transmission 512 …… Primary radiation used for reception Switch to switch the vessel 513… Transmission channel 1 signal input 514 ...... transmission channel 2 signal input 515 ...... reception channel 1 signal output 516 ...... receive channel 2 signal output

Claims (1)

[Claims] 1. In a satellite communication system comprising n (n is a natural number of 2 or more) communication satellites and a plurality of earth stations, the earth station in the system has a multi-beam antenna, and all the satellites in the system are provided. The satellites are always tracked by making one beam direction correspond to each other, and a specific m (m is a natural number satisfying m ≦ n) pointing directions are selected from among these beam directions to select an arbitrary direction in the system. A multi-satellite satellite communication earth station apparatus capable of instantaneously selecting m satellites and performing communication without loss of information by using the selected satellites for relaying.