JP2005253120A - Earth station apparatus, satellite communication system, communication system, and ground terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform efficiently a handover, when two or more dynamic satellites meets in a predetermined rendezvous point. <P>SOLUTION: When a satellite (1) 21 and a satellite (2) 22 are not near the rendezvous point, an earth station 30 receives a signal 201 of n channel by a frequency band of F1'-Fn' from the satellite (1) 21.When the satellite (1) 21 and the satellite (2) 22 are close to the rendezvous point, an earth station 30 transmits a control signal, turns on a Sync Word2211 of the satellite (2) 22, and transmits a signal 202 of the same n channel by frequency band F1''-Fn'' from the satellite (2). After receiving a signal 201 and a signal 202 duplicated in parallel from the satellite (1) 21 and the satellite (2) 22 duaring a certain time interval, it transmits a control signal to the satellite (1) 21, turns off the Sync Word2111, stops transmission of the signal 201 from the satellite (1) 21, and conducts handover from the satellite (1) 21 to the satellite (2) 22. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a technique for communicating with a non-geostationary satellite operating in a predetermined satellite orbit, and more particularly to a technique for efficiently performing a handover when a plurality of non-geostationary satellites meet at a predetermined meeting point. .

  In recent years, introduction of communication services using non-geostationary satellites (hereinafter referred to as “non-geostationary satellites”) has been studied. Unlike a geostationary satellite, a non-geostationary satellite does not stay above the communication service area and leaves the communication service area when time passes. Therefore, in order to realize a communication service using a non-geostationary satellite, a plurality of non-geostationary satellites are used, and another non-geostationary satellite is moved to the communication service area before one non-geostationary satellite leaves the communication service area. So that there is always at least one non-geostationary satellite over the communication service area. If the satellite orbit of a non-stationary satellite leaving the communication service area and the satellite orbit of a non-stationary satellite newly arriving in the communication service area cross over the communication service area, the two non-stationary satellites intersect (meeting) However, in order to continue the communication service, it is necessary to perform a handover between the two non-geostationary satellites when the two non-geostationary satellites intersect (meet).

Conventionally, there has been no technique for performing handover between non-geostationary satellites when these two non-geostationary satellites meet.
JP 2001-111469 A Special table 2003-504940 gazette JP 2001-025050 A

  In view of the above, the main object of the present invention is to provide a technique for efficiently performing handover between non-stationary satellites when a plurality of non-stationary satellites meet.

The earth station device according to the present invention is
An earth station device capable of receiving signals from each of the first artificial satellite and the second artificial satellite,
In addition to receiving a signal from the first artificial satellite, the artificial satellite receiving the signal is switched from the first artificial satellite to the second artificial satellite in a predetermined case.

The earth station device
A signal can be received from a first satellite operating in a predetermined satellite orbit,
A corresponding signal corresponding to the signal transmitted by the first artificial satellite can be received from the second artificial satellite operating on the satellite orbit different from the satellite orbit of the first artificial satellite and meeting with the first artificial satellite,
When the distance between the first satellite and the second satellite is greater than or equal to the predetermined distance,
Receive the signal from the first satellite,
When the distance between the first satellite and the second satellite is less than a predetermined distance,
Start receiving the corresponding signal from the second artificial satellite and stop receiving the signal from the first artificial satellite, and switch the artificial satellite that receives the signal from the first artificial satellite to the second artificial satellite. Features.

The earth station device
A plurality of channels of signals can be received from each of the first satellite and the second satellite,
A plurality of channels of signals are received from the first artificial satellite, and in a predetermined case, the artificial satellite that receives the signals is sequentially switched from the first artificial satellite to the second artificial satellite for each channel.

The earth station device
From the first satellite operating in a predetermined satellite orbit, it is possible to receive signals of multiple channels in individual frequency bands for each channel,
Correspondence of multiple channels corresponding to the signals of multiple channels transmitted by the first satellite from the second satellite operating on the satellite orbit different from the satellite orbit of the first artificial satellite and meeting with the first artificial satellite The signal can be received,
When the distance between the first satellite and the second satellite is greater than or equal to the predetermined distance,
Receive multiple channel signals from the first satellite in separate frequency bands for each channel,
When the distance between the first satellite and the second satellite is less than a predetermined distance,
For a specific channel, start receiving the corresponding signal from the second artificial satellite in a predetermined frequency band and stop receiving the signal from the first artificial satellite to receive the signal of the corresponding channel. Switch from the artificial satellite to the second artificial satellite, open the frequency band used for signal reception from the first artificial satellite as an empty frequency band,
For the other channels, in sequence for each channel, start receiving the corresponding signal from the second artificial satellite in the free frequency band and stop receiving the signal from the first artificial satellite to receive the signal from the first artificial satellite. The process of releasing the frequency band used in the above as an empty frequency band is repeated, and the satellite that receives signals is switched from the first artificial satellite to the second artificial satellite for a plurality of channels.

The earth station device
When the distance between the first satellite and the second satellite is less than a predetermined distance,
After receiving the corresponding signal from the second artificial satellite, stop receiving the signal from the first artificial satellite, and switch the artificial satellite that receives the signal from the first artificial satellite to the second artificial satellite. Features.

The earth station device
When the distance between the first satellite and the second satellite is less than a predetermined distance,
At the same time as the reception of the corresponding signal from the second artificial satellite is started, the reception of the signal from the first artificial satellite is stopped, and the artificial satellite that receives the signal is switched from the first artificial satellite to the second artificial satellite. It is characterized by that.

The earth station device
A signal can be received from the first artificial satellite in a predetermined frequency band,
The corresponding signal can be received from the second satellite in a frequency band different from the frequency band of the first satellite,
When the distance between the first satellite and the second satellite is less than a predetermined distance,
The reception of the corresponding signal from the second artificial satellite is started in a frequency band different from the frequency band of the first artificial satellite.

The earth station device
Multiple channels can be received for each group from the first satellite that groups multiple channels into two or more channels and manages multiple channels in groups.
Multiple channels can be received for each group from the second satellite that groups multiple channels in correspondence with grouping in the first satellite and manages the channels in groups.
Receives multiple channels of signals from the first artificial satellite for each group, and switches the artificial satellites that receive signals from the first artificial satellite to the second artificial satellite for each group in a predetermined case. And

The earth station device
From the first satellite operating in a predetermined satellite orbit, multiple channel signals can be received in individual frequency bands for each group,
Correspondence of multiple channels corresponding to the signals of multiple channels transmitted by the first satellite from the second satellite operating on the satellite orbit different from the satellite orbit of the first artificial satellite and meeting with the first artificial satellite The signal can be received for each group,
When the distance between the first satellite and the second satellite is greater than or equal to the predetermined distance,
Receive multiple channel signals from the first satellite in separate frequency bands for each group,
When the distance between the first satellite and the second satellite is less than a predetermined distance,
For a specific group, start receiving the corresponding signal from the second artificial satellite in a predetermined frequency band and stop receiving the signal from the first artificial satellite to receive the signal of the group. Switch from the artificial satellite to the second artificial satellite, open the frequency band used for signal reception from the first artificial satellite as an empty frequency band,
For the other groups, in order for each group, the reception of the corresponding signal from the second artificial satellite is started in the vacant frequency band and the reception of the signal from the first artificial satellite is stopped and the reception of the signal from the first artificial satellite is stopped. The process of releasing the frequency band used in the above as an empty frequency band is repeated, and the satellite that receives signals is switched from the first artificial satellite to the second artificial satellite for a plurality of channels.

The earth station device according to the present invention is
An earth station device capable of transmitting a signal to each of the first artificial satellite and the second artificial satellite,
A signal is transmitted to the first artificial satellite, and the artificial satellite to which the signal is transmitted is switched from the first artificial satellite to the second artificial satellite in a predetermined case.

The earth station device
A signal can be transmitted to the first artificial satellite operating in a predetermined satellite orbit,
A corresponding signal corresponding to the signal transmitted to the first satellite is transmitted to a second satellite that operates on a different satellite orbit from the satellite orbit of the first satellite and meets the first satellite. Can be sent,
When the distance between the first satellite and the second satellite is greater than or equal to the predetermined distance,
Send a signal to the first satellite,
When the distance between the first satellite and the second satellite is less than a predetermined distance,
Start transmission of the corresponding signal to the second artificial satellite and stop signal transmission to the first artificial satellite, and switch the artificial satellite to which the signal is transmitted from the first artificial satellite to the second artificial satellite. It is characterized by.

The earth station device
A multi-channel signal can be transmitted to each of the first satellite and the second satellite,
Transmits multiple channels of signals to the first artificial satellite and, in a predetermined case, switches the satellite to which the signal is transmitted from the first artificial satellite to the second artificial satellite in order for each channel. And

The earth station device
Multiple channel signals can be transmitted in individual frequency bands for each channel to the first satellite operating in a predetermined satellite orbit,
A second channel which associates a plurality of channels corresponding to a plurality of channels transmitted to the first satellite on a satellite orbit different from the satellite orbit of the first satellite and associates with the first satellite. Can be sent to
When the distance between the first satellite and the second satellite is greater than or equal to the predetermined distance,
Transmit multiple channel signals to the first satellite in separate frequency bands for each channel,
When the distance between the first satellite and the second satellite is less than a predetermined distance,
For a specific channel, transmission of the corresponding signal to the second artificial satellite is started in a predetermined frequency band, and signal transmission to the first artificial satellite is stopped, so that the artificial satellite to which the signal of the channel is transmitted is the first Switch from artificial satellite to second artificial satellite, open the frequency band used for signal transmission to the first artificial satellite as an empty frequency band,
For other channels, transmission of the corresponding signal to the second artificial satellite is started in the empty frequency band in order for each channel, and signal transmission to the first artificial satellite is stopped and used for signal transmission to the first artificial satellite. The process of releasing the set frequency band as an empty frequency band is repeated, and the satellite to which the signal is transmitted is switched from the first artificial satellite to the second artificial satellite for a plurality of channels.

The earth station device
When the distance between the first satellite and the second satellite is less than a predetermined distance,
After starting the transmission of the corresponding signal to the second artificial satellite, the signal transmission to the first artificial satellite is stopped, and the artificial satellite to which the signal is transmitted is switched from the first artificial satellite to the second artificial satellite. It is characterized by that.

The earth station device
When the distance between the first satellite and the second satellite is less than a predetermined distance,
At the same time as the transmission of the corresponding signal to the second artificial satellite is started, the signal transmission to the first artificial satellite is stopped, and the artificial satellite to which the signal is transmitted is changed from the first artificial satellite to the second artificial satellite. It is characterized by switching to.

The earth station device
A signal can be transmitted in a predetermined frequency band to the first artificial satellite, and a corresponding signal can be transmitted in a frequency band different from the frequency band of the first artificial satellite to the second artificial satellite,
When the distance between the first satellite and the second satellite is less than a predetermined distance,
The transmission of the corresponding signal to the second artificial satellite is started in a frequency band different from the frequency band of the first artificial satellite.

The earth station device
Multiple channel signals can be transmitted for each group to the first satellite that groups multiple channels into two or more channels and manages multiple channels in groups.
In response to the grouping in the first artificial satellite, a plurality of channels can be grouped and a plurality of channels can be transmitted for each group to the second artificial satellite managing the plurality of channels in units of groups.
The multi-channel signal is transmitted for each group to the first artificial satellite, and the signal transmission destination artificial satellite is switched sequentially from the first artificial satellite to the second artificial satellite for each group in a predetermined case. It is characterized by that.

The earth station device
For the first satellite operating in a predetermined satellite orbit, signals of multiple channels can be transmitted in individual frequency bands for each group,
A second channel which associates a plurality of channels corresponding to a plurality of channels transmitted to the first satellite on a satellite orbit different from the satellite orbit of the first satellite and associates with the first satellite. Can be sent to each satellite for each group,
When the distance between the first satellite and the second satellite is greater than or equal to the predetermined distance,
Send multiple channel signals to the first satellite in separate frequency bands for each group,
When the distance between the first satellite and the second satellite is less than a predetermined distance,
For a specific group, start transmission of a corresponding signal to the second satellite in a predetermined frequency band and stop transmission of the signal to the first satellite, so that the satellite to which the signal of the group is transmitted is the first Switch from artificial satellite to second artificial satellite, open the frequency band used for signal transmission to the first artificial satellite as an empty frequency band,
For the other groups, in order for each group, transmission of the corresponding signal to the second artificial satellite is started in the vacant frequency band, and signal transmission to the first artificial satellite is stopped and used for signal transmission to the first artificial satellite. The process of releasing the set frequency band as an empty frequency band is repeated, and the satellite to which the signal is transmitted is switched from the first artificial satellite to the second artificial satellite for a plurality of channels.

The satellite communication device according to the present invention is
A satellite communication device that is mounted on an artificial satellite that operates on a predetermined satellite orbit and meets another artificial satellite, and that can transmit a signal to the earth station device,
When the distance between the onboard satellite and the other satellite is more than the specified distance,
Send a signal to the earth station device,
When the distance between the onboard satellite and other satellites is less than the predetermined distance,
Signal transmission to the earth station device is stopped.

The satellite communication device is
It is mounted on an artificial satellite that meets other artificial satellites that can transmit signals to the earth station device.
Another artificial satellite transmits signals to the earth station device in a frequency band different from the frequency band used for signal transmission to the earth station device.

The satellite communication device is
Multiple channel signals can be transmitted to the earth station device.
When the distance between the onboard satellite and other satellites is less than the predetermined distance,
Signal transmission to the earth station apparatus is stopped in order for each channel.

The satellite communication device is
Multiple channels can be grouped into two or more channels, and multiple channels can be managed in groups, and multiple channel signals can be transmitted to the earth station device for each group.
When the distance between the onboard satellite and other satellites is less than the predetermined distance,
Signal transmission to the earth station apparatus is stopped in order for each group.

The satellite communication device according to the present invention is
A satellite communication device that is mounted on an artificial satellite that operates on a predetermined satellite orbit and meets another artificial satellite, and that can receive a signal from an earth station device,
When the distance between the onboard satellite and the other satellite is more than the specified distance,
Receive signals from the earth station equipment,
When the distance between the onboard satellite and other satellites is less than the predetermined distance,
Signal reception from the earth station device is stopped.

The satellite communication device is
It is mounted on a satellite that meets other satellites that can receive signals from the earth station device.
Another artificial satellite receives signals from the earth station device in a frequency band different from the frequency band used for signal reception from the earth station device.

The satellite communication device is
It can receive multiple channels of signals from the earth station device,
When the distance between the onboard satellite and other satellites is less than the predetermined distance,
Signal reception from the earth station device is stopped in order for each channel.

The satellite communication device is
Multiple channels can be grouped into two or more channels, and multiple channels can be managed in groups, and multiple channel signals can be received from the earth station device for each group.
When the distance between the onboard satellite and other satellites is less than the predetermined distance,
Signal reception from the earth station device is stopped in order for each group.

The satellite communication device according to the present invention is
A satellite communication device that is mounted on an artificial satellite that operates on a predetermined satellite orbit and meets another artificial satellite, and that can transmit a signal to the earth station device,
When the distance between the onboard satellite and the other satellite is less than the predetermined distance,
Signal transmission to the earth station device is started.

The satellite communication device is
Signals of multiple channels are transmitted to the earth station device in individual frequency bands for each channel, and in a predetermined case, signal transmission is stopped sequentially for each channel and the frequency band used for signal transmission is released as an empty frequency band. On board satellites that meet other satellites,
A multi-channel corresponding signal corresponding to a multi-channel signal transmitted by another artificial satellite can be transmitted to the earth station device,
When the distance between the onboard satellite and other satellites is less than the predetermined distance,
For a specific channel, start transmission of a corresponding signal to the earth station device in a predetermined frequency band, and detect a free frequency band that is released when other artificial satellites stop signal transmission of the channel,
For other channels, in order for each channel, transmission of the corresponding signal to the earth station device is started in the detected vacant frequency band, and the vacant frequency band released when other artificial satellites stop signal transmission is detected. This process is repeated, and transmission of corresponding signals is started for a plurality of channels.

The satellite communication device is
It is mounted on an artificial satellite that meets other artificial satellites that can transmit signals to the earth station device.
Another artificial satellite transmits signals to the earth station device in a frequency band different from the frequency band used for signal transmission to the earth station device.

The satellite communication device is
Multiple channel signals can be transmitted to the earth station device.
When the distance between the onboard satellite and other satellites is less than the predetermined distance,
Signal transmission to the earth station device is started sequentially for each channel.

The satellite communication device is
Multiple channels can be grouped into two or more channels, and multiple channels can be managed in groups, and multiple channel signals can be transmitted to the earth station device for each group.
When the distance between the onboard satellite and other satellites is less than the predetermined distance,
Signal transmission to the earth station device is started in order for each group.

The satellite communication device is
Multiple channels are grouped into two or more channels, multiple channels are managed in groups, and multiple channel signals are transmitted to the earth station device in individual frequency bands for each group, and signal transmission is performed sequentially for each group in a given case. Is mounted on an artificial satellite that is associated with other artificial satellites that release the frequency band used for signal transmission as an empty frequency band,
Multiple channels are grouped according to the grouping by other artificial satellites, and the multiple channels are managed in units of groups, and the corresponding signals of multiple channels corresponding to the multiple channel signals transmitted by other artificial satellites are Can be transmitted to the station equipment,
When the distance between the onboard satellite and other satellites is less than the predetermined distance,
For a specific group, start transmission of a corresponding signal to the earth station device in a predetermined frequency band, and detect a free frequency band that has been released due to the other satellites stopping the signal transmission of the group,
For other groups, processing for detecting a free frequency band that is released when other artificial satellites stop transmitting signals while starting transmission of corresponding signals to the earth station device in the detected free frequency band in order for each group Is repeated, and transmission of corresponding signals is started for a plurality of channels.

The satellite communication device according to the present invention is
A satellite communication device that is mounted on an artificial satellite that operates on a predetermined satellite orbit and meets another artificial satellite, and that can receive a signal from an earth station device,
When the distance between the onboard satellite and the other satellite is less than the predetermined distance,
Signal reception from the earth station device is started.

The satellite communication device is
Other signals that receive signals of multiple channels from the earth station device in individual frequency bands for each channel, stop signal reception for each channel in order, and open the frequency band used for signal reception as an empty frequency band On board satellites that meet with satellites,
A multi-channel corresponding signal corresponding to a multi-channel signal received by another artificial satellite can be received from the earth station device,
When the distance between the onboard satellite and other satellites is less than the predetermined distance,
For a specific channel, start receiving a corresponding signal from the earth station device in a predetermined frequency band, and detect a free frequency band that has been released because other satellites stopped receiving the signal of the channel,
For other channels, in order for each channel, a process of starting reception of a corresponding signal from the earth station device in the detected vacant frequency band and detecting an vacant frequency band that has been released when other artificial satellites stopped receiving signals. Is repeated, and reception of corresponding signals is started for a plurality of channels.

The satellite communication device is
It is mounted on an artificial satellite that meets other artificial satellites that receive signals from the earth station device.
Another artificial satellite receives signals from the earth station device in a frequency band different from the frequency band used for signal reception from the earth station device.

The satellite communication device is
It can receive multiple channels of signals from the earth station device,
When the distance between the onboard satellite and other satellites is less than the predetermined distance,
Signal reception from the earth station device is sequentially started for each channel.

The satellite communication device is
Multiple channels can be grouped into two or more channels, and multiple channels can be managed in groups, and multiple channel signals can be received from the earth station device for each group.
When the distance between the onboard satellite and other satellites is less than the predetermined distance,
Signal reception from the earth station device is started in order for each group.

The satellite communication device is
Multiple channels are grouped into two or more channels, the multiple channels are managed in groups, and multiple channel signals are received for the earth station device in separate frequency bands for each group. Is installed in a satellite that is associated with other satellites that release the frequency band used for signal reception as an empty frequency band,
Multiple channels are grouped in response to grouping by other satellites, and multiple channels are managed in groups, and multiple channel correspondence signals corresponding to the multiple channel signals received by other satellites are Can be received from the station device,
When the distance between the onboard satellite and other satellites is less than the predetermined distance,
For a specific group, start receiving a corresponding signal in a predetermined frequency band from the earth station device, and detect a free frequency band released by the other artificial satellites stopped receiving the signal of the group,
For other groups, in order for each group, in order to detect a free frequency band that has been released by starting reception of a corresponding signal from the earth station device in the detected free frequency band and stopping other satellites from receiving signals Is repeated, and reception of corresponding signals is started for a plurality of channels.

The communication device according to the present invention is
Connected to the earth station device that can receive signals from each of the first satellite and the second satellite, and transmitted from either the first satellite or the second satellite via the earth station device A communication device for receiving a signal,
While receiving a signal from the first artificial satellite and, in a predetermined case, via the earth station device that switches the artificial satellite that receives the signal from the first artificial satellite to the second artificial satellite,
A signal transmitted from either the first artificial satellite or the second artificial satellite is received.

The communication device
An earth station device,
It is possible to receive signals from multiple channels in the individual frequency band for each channel from the first satellite operating in the specified satellite orbit, and operate in a satellite orbit different from the satellite orbit of the first satellite. From a second satellite associated with one satellite, a corresponding signal of a plurality of channels corresponding to a signal of a plurality of channels transmitted by the first satellite can be received,
When the distance between the first satellite and the second satellite is greater than or equal to the predetermined distance,
Receive multiple channel signals from the first satellite in separate frequency bands for each channel,
When the distance between the first satellite and the second satellite is less than a predetermined distance,
For a specific channel, start receiving the corresponding signal from the second artificial satellite in a predetermined frequency band and stop receiving the signal from the first artificial satellite to receive the signal of the corresponding channel. Switch from the artificial satellite to the second artificial satellite, open the frequency band used for signal reception from the first artificial satellite as an empty frequency band,
For the other channels, in sequence for each channel, start receiving the corresponding signal from the second artificial satellite in the free frequency band and stop receiving the signal from the first artificial satellite to receive the signal from the first artificial satellite. Through the process of releasing the frequency band used for the vacant frequency band, through an earth station device that switches the satellite that receives the signal from the first artificial satellite to the second artificial satellite for a plurality of channels,
A signal transmitted from either the first artificial satellite or the second artificial satellite is received.

The communication device
An artificial satellite capable of receiving a signal of a plurality of channels from each of the first artificial satellite and the second artificial satellite, receiving a signal of a plurality of channels from the first artificial satellite, and receiving a signal in a predetermined case. Through the earth station that switches from the first satellite to the second satellite in turn for each channel,
A signal transmitted from either the first artificial satellite or the second artificial satellite is received.

  According to the present invention, when the distance between the first artificial satellite and the second artificial satellite is less than the predetermined distance, the artificial satellite that receives the signal is changed from the first artificial satellite to the second artificial satellite. Can be switched.

  Further, according to the present invention, since the frequency band for receiving a signal from the first artificial satellite is different from the frequency band for receiving a corresponding signal from the second artificial satellite, it is possible to avoid errors due to radio wave interference or the like. it can.

  Further, according to the present invention, since artificial satellites that sequentially receive signals for each channel are switched using a vacant frequency band for signals of a plurality of channels, frequency resources can be used efficiently.

  Furthermore, according to the present invention, since a plurality of channels are grouped into two or more channels and the satellites that receive signals are switched in order for each group, the time required for switching can be shortened.

  According to the present invention, when the distance between the first artificial satellite and the second artificial satellite becomes less than the predetermined distance, the signal transmission destination artificial satellite is changed from the first artificial satellite to the second artificial satellite. Can be switched to.

  Further, according to the present invention, since the frequency band for transmitting a signal to the first artificial satellite is different from the frequency band for transmitting a corresponding signal to the second artificial satellite, it is possible to avoid errors due to radio wave interference or the like. it can.

  Further, according to the present invention, since a satellite to which a signal is transmitted is switched in order for each channel using a vacant frequency band for signals of a plurality of channels, frequency resources can be used efficiently.

Embodiment 1 FIG.
FIG. 1 is a principle diagram showing a configuration example of a satellite communication system according to the present embodiment.

  In FIG. 1, reference numeral 10a denotes a ground terminal 1 that transmits signals (101, 102) to a non-geostationary satellite in the frequency band f1. The signal 101 is a signal for the non-geostationary satellite (1) 21, and the signal 102 is a signal for the non-geostationary satellite (2) 22. The contents of the signal 101 and the signal 102 are the same.

  10n is a ground terminal n that transmits signals (103, 104) to the non-geostationary satellite in the frequency band fn. The signal 103 is a signal for the non-geostationary satellite (1) 21, and the signal 104 is a signal for the non-geostationary satellite (2) 22. The contents of the signal 103 and the signal 104 are the same.

  The frequency band f1 and the frequency band fn are different frequency bands.

  The signals transmitted from each of the ground terminals 1 to n are each treated as a signal for one channel. For example, the signals 101 and 102 transmitted from the ground terminal 1 are channel 1 signals (Ch1 signals), Signals 103 and 104 transmitted from the ground terminal n are channel n signals (Chn signals).

  In FIG. 1, only two units of the ground terminal 1 and the ground terminal n are shown, but it is assumed that there are ground terminals 2 to n-1 in addition to these.

  The ground terminal is a communication device mounted on a vehicle, for example.

  Reference numeral 21 denotes a non-stationary satellite (1) that orbits the earth (hereinafter simply referred to as “satellite (1)”). The satellite (1) 21 receives signals for n channels of Ch1 to Chn transmitted from the ground terminals 1 to n, multiplexes the received signals of Ch1 to Chn, performs frequency conversion, and performs frequency conversion from the frequency band F1 ′ to The n-channel signal 201 of Fn ′ is transmitted to the earth station device 30. Here, the frequency bands F1 ′ to Fn ′ correspond to signals received from the ground terminal, and the frequency band F1 ′ is a frequency band after frequency conversion for the Ch1 signal 101 received from the ground terminal 1, Fn ′ is a frequency band after frequency conversion for the Chn signal 103 received from the ground terminal n. As described above, the satellite (1) 21 receives the signals of a plurality of channels, converts the signals of the plurality of channels into individual frequency bands for each channel, and transmits them to the earth station 30.

  Reference numeral 22 denotes a non-stationary satellite (2) that orbits the earth (hereinafter simply referred to as “satellite (2)”). The satellite (2) 22 receives the signals for n channels of Ch1 to Chn transmitted from the ground terminals 1 to n, multiplexes the received signals of Ch1 to Chn, performs frequency conversion, and performs the frequency band F1 ″. Signals 202 for ~ Fn ″ for n channels are transmitted to the earth station device 30. Here, the frequency bands F1 ″ to Fn ″ correspond to signals received from the ground terminal, and the frequency band F1 ″ is a frequency band after frequency conversion for the Ch1 signal 102 received from the ground terminal 1. The frequency band Fn ″ is a frequency band after frequency conversion for the Chn signal 104 received from the ground terminal n. As described above, the satellite (2) 22 receives the signals of a plurality of channels, converts the signals of the plurality of channels into individual frequency bands for each channel, and transmits them to the earth station 30.

  The reason why the frequency bands of the transmission signals from the satellite (1) 21 and the satellite (2) 22 are different is to avoid errors due to radio wave interference or the like.

  The satellite (1) 21 and the satellite (2) 22 orbit each individual satellite orbit, but each satellite orbit has a position that intersects the satellite orbit of the other satellite, and the satellite (1) 21 and the satellite (1) 21 and The satellite (2) 22 intersects at a position where the satellite orbits intersect. The intersection of a plurality of satellites is called a meeting, and the position where a plurality of non-stationary satellites meet is called a meeting point.

  In the satellite communication system according to the present embodiment, satellite (1) 21 and satellite (2) 22 reach the vicinity of the meeting point, and the distance between satellite (1) 21 and satellite (2) 22 is predetermined. When the distance becomes less than the distance, the handover is performed between the satellite (1) 21 and the satellite (2) 22. Here, the meaning that the distance between the satellite (1) 21 and the satellite (2) 22 is less than a predetermined distance means that the signal beam of a certain antenna is both the satellite (1) 21 and the satellite (2) 22. It means to reach against.

  In FIG. 1, the satellite (1) 21 is a non-stationary satellite that is used for communication before the handover, and the satellite (2) 22 is a non-stationary satellite that is used for communication after the handover. Note that the satellite used before the handover corresponds to the first artificial satellite, and the satellite used after the handover corresponds to the second artificial satellite. Therefore, in FIG. 1, the satellite (1) 21 corresponds to an example of a first artificial satellite, and the satellite (2) corresponds to an example of a second artificial satellite. At the time of handover, the satellite (2), which is the second artificial satellite, transmits a corresponding signal corresponding to the signal transmitted by the satellite (1), which is the first artificial satellite. For example, at the time of handover, the satellite (2) that is the second artificial satellite transmits the same signal as the signal transmitted by the satellite (1) that is the first artificial satellite.

  The satellite (1) 21 and the satellite (2) 22 are, for example, quasi-zenith satellites. The quasi-zenith satellite will be described later.

  In FIG. 1, reference numeral 30 denotes an earth station device that receives signals from the satellite (1) 21 and the satellite (2) 22 (hereinafter simply referred to as “earth station”). The earth station 30 can receive the signals 201 of the frequencies F1 ′ to Fn ′ from the satellite (1) 21 before the handover, and the signals 202 of the frequencies F1 ″ to Fn ″ after the handover. 2) Receivable from 22. The earth station 30 controls handover by instructing the satellite (1) 21 to stop transmitting the signal 201 or instructing the satellite (2) 22 to start transmitting the signal 202.

  Reference numerals 40 to 60 denote communication devices that are connected to the earth station 30 and receive signals received from the earth station 30 by the earth station 30 from the satellite (1) 21 and the satellite (2) 22.

  In the present embodiment, at the time of handover near the meeting point, the transmission signal from the ground terminal is received by both satellites. In order to prevent instantaneous communication interruption, the received transmission signal from the ground terminal is converted into a separate frequency band by each satellite, and the satellite (1) 21 receives the signal 201 of the frequency bands F1 ′ to Fn ′, the satellite (2 ) 22 are overlapped for a certain period of time as signals 202 in the frequency bands F1 ″ to Fn ″ and transmitted to the earth station 30. As soon as the handover is completed, the satellite (1) stops the transmission signal. The satellite (1) 21 and the satellite (2) 22 have different frequency bands (F1 ′ to Fn ′ ≠ F1 ″ to Fn ″). It is because it receives. When high bit rates with the same content are received from two locations, the frequency band is changed because the transmission distance is different and the timing is shifted and correct reception cannot be performed.

  In this case, the relationship between the frequency and time of the signal received by the earth station 30 is as shown in FIG. In FIG. 2, the horizontal axis represents time and the vertical axis represents frequency. SW01 is a switch in the earth station 30 that turns on / off reception of the signal of the satellite (1) 21. SW02 is a switch in the earth station 30 that turns on / off reception of the signal of the satellite (2) 22. SW11 is a switch in the earth station 30 that switches an output signal to the communication devices 40 to 60 of the earth station 30 to a signal from the satellite (1) 21 or a signal from the satellite (2).

  The earth station 30 receives the signals of the channels 1 to n from the satellite (1) 21 at the frequency of F1 ′ to Fn ′, while receiving the signals of the channels 1 to n from the satellite (2) 22 to F1 ″ to Fn ″. Starts receiving at the frequency of (SW02 is ON). The output signal from the earth station 30 to the communication devices 40 to 60 is switched from the signal of the satellite (1) 21 to the signal of the satellite (2) 22 after a predetermined period has elapsed after the start of signal reception from the satellite (2) ( SW11 switching). Thereafter, signal reception from the satellite (1) is stopped (SW01 is turned OFF). The switching operation of SW01, SW02, and SW11 will be described later.

  Here, the quasi-zenith satellite will be described.

  FIG. 25 is a diagram for explaining the locus of the quasi-zenith satellite. In FIG. 25, reference numeral 200 denotes the quasi-zenith satellite.

  The quasi-zenith satellite 200 orbits once a day according to the rotation of the earth so as to have an inclination angle of about 45 degrees from the equator plane. Note that the inclination angle from the equator plane may be arbitrarily set depending on the design. In addition, three quasi-zenith satellites 200 are arranged so as to be 120 degrees apart at the ascending intersection eclipse (intersection with the equator plane).

  FIG. 26 is a diagram for explaining the locus of the quasi-zenith satellite orbit projected on the ground surface.

  FIG. 26 shows the locus of the quasi-zenith satellite 200 in FIG. 25 when the ground is fixed. As shown in FIG. 26, when the ground is fixed, the quasi-zenith satellite 200 orbits so as to draw an “eighth-shape” having an intersection on the equator. Although the three quasi-zenith satellites 200 have different orbital planes, the quasi-zenith satellites 200 are located above Japan without any break by changing (meeting) every eight hours. Further, when considering the region in Japan, there is always a quasi-zenith satellite 200 having an elevation angle of 70 degrees or more. Because it is located above Japan without a break, there is always a quasi-zenith satellite 200 with an elevation angle of 70 degrees or more, and when the receiver receives radio waves from the quasi-zenith satellite 200 on the ground, the radio waves can be blocked even in the valleys of the building. Less is.

  As described above, since the quasi-zenith satellite changes (meetings) over Japan every 8 hours, it is between the quasi-zenith satellite that is about to reach Japan and the quasi-zenith satellite that is about to leave Japan. Therefore, it is necessary to perform handover every 8 hours. For this reason, the satellite communication system according to the present embodiment can be applied to the quasi-zenith satellite.

  Next, an example of the internal configuration of the satellite (1) 21 and the satellite (2) 22 will be described with reference to FIG.

  In FIG. 3, the description will focus on the parts related to communication with the ground terminal and the earth station.

  For the satellite (1), 210 is a satellite communication device (1) that communicates with the ground terminal and the earth station. The internal configuration of the satellite communication device (1) 210 will be described later.

  Reference numeral 230 denotes an input antenna that receives the signals 101, 103, and 105 from the ground terminals 1 to n. As shown in FIG. 5, the input antenna 230 receives signals 101, 103, and 105 for n channels in the frequency bands f1 to fn transmitted from the ground terminals 1 to n, and multiplexes these signals to generate signals. 107. The numbers in parentheses indicate the state of the input antenna 240 in the satellite (2) 22, and the signals 102, 104, and 106 are multiplexed into the signal 108 also in the input antenna 240 of the satellite (2) 22.

  Reference numeral 250 denotes an output antenna that transmits a signal to the earth station 30. The output antenna 250 transmits to the earth station 30 a signal 201 for n channels in the frequency band of F1 ′ to Fn ′ after frequency conversion.

  Reference numeral 270 denotes a control signal antenna that receives a control signal from the earth station 30. The control signal is a signal or the like for instructing ON / OFF of a switch in the satellite communication device (1) 210.

  Next, the internal configuration of the satellite communication device (1) 210 will be described.

  Reference numeral 211 denotes an internal circuit that performs frequency conversion on the signal 107 (frequency bands f1 to fn) received by the input antenna 230 and outputs the signal 109 in the frequency band of F1 ′ to Fn ′ to the output antenna 250. The internal circuit 211 includes a SW (switch) 2111 and a frequency converter (hereinafter simply referred to as “converter”) 2112. The SW 2111 blocks signal input at the timing of stopping signal transmission to the earth station 30. As shown in FIG. 6, the converter 2112 receives the signal 107 of the frequency bands f1 to fn, performs frequency conversion, and outputs the signal 109 of the frequency bands F1 'to Fn'.

  Reference numeral 212 denotes a control signal receiving unit that receives a control signal from the control signal antenna 270. The control signal includes an ON / OFF instruction for SW2111.

Reference numeral 213 denotes an SW control unit that switches ON / OFF of the SW 2111 based on the ON / OFF instruction of the control signal.
SW control unit.

  The internal configuration of the satellite (2) 22 is the same as that of the satellite (1) 21.

  In the satellite (2) 22, the input antenna 240 receives the signals 102, 104, and 106 in the frequency bands f1 to fn from the ground terminals 1 to n and multiplexes them into the signal 108, but the converter of the internal circuit 221 2212 converts the signal 110 in the frequency band F1 ″ to Fn ″ (FIG. 6), and outputs the signal 202 in the frequency band F1 ″ to Fn ″ from the output antenna.

  The control signal antenna 280 receives a control signal for instructing ON / OFF of the SW 2211, and the SW control unit 223 switches ON / OFF of the SW 2211 based on the ON / OFF instruction of the control signal.

  Next, the internal configuration of the earth station 30 will be described with reference to FIG.

  Reference numeral 301 denotes an antenna (1) directed to the satellite (1) 21, and reference numeral 302 denotes an antenna (2) directed to the satellite (2) 22.

  Reference numeral 303 denotes an SW (switch) 01 for switching reception of the signal 201 (frequency band F1 ′ to Fn ′) of the satellite (1) received by the antenna (1) 301, and 304 denotes an antenna (2) 302. SW (switch) 02 that performs reception switching of the received satellite (2) signal (frequency band F1 ″ to Fn ″).

  Reference numeral 305 denotes a demodulation unit that performs demodulation processing on the signals (frequency bands F1 ′ to Fn ′) of the satellite (1) received by the antenna (1) 301. Reference numeral 306 denotes the satellite received by the antenna (2) 302. It is a demodulator that demodulates the signal (2) (frequency bands F1 ″ to Fn ″).

  Reference numerals 307 and 308 denote delay units. The delay units 307 and 308 include a delay time from the ground terminal → satellite (1) → SW11 (309) and a delay time from the ground terminal → satellite (2) → SW11 (309). Adjust so that they are the same.

  A switch 309 switches the input from the delay unit 307 and the input from the delay unit 308, and outputs the signal from the satellite (1) or the signal from the satellite (2) to the communication devices 40 to 60 as information data. (Switch) 11. As shown in FIG. 2, the earth station 30 receives signals redundantly from the satellite (1) and the satellite (2), and outputs the output signal to the communication devices 40 to 60 by switching the SW11 at a specific time. The signal of (1) is switched to the signal of satellite (2).

  A switching control unit 310 controls various switching timings. The switching control unit 310 controls the SW2111 OFF timing of the satellite (1) 21, the ON timing of the SW 2211 of the satellite (2) 22, the SW01 switching timing, the SW02 switching timing, the SW11 switching timing, and the like. The switching control unit 310 has a function of detecting the positions of the satellite (1) and the satellite (2), and when detecting that the satellite (1) and the satellite (2) have reached the vicinity of the meeting point, The SW 2111 OFF timing of the satellite (1) 21 and the SW 2211 ON timing of the satellite (2) 22 are calculated, and the control signal generator 311, SW01 / SW02 controller 314, and SW11 controller 315 are instructed to switch.

  311 is a control signal generation unit that generates a control signal for instructing the satellite (1) 21 to turn off SW2111 and a control signal for instructing the satellite (2) 22 to turn on SW2211, based on an instruction from the switching control unit 310. is there. The control signal may be generated as a pulse signal, for example, or may be generated as a signal such as Bilevel.

  Reference numeral 312 denotes a control signal transmission unit that performs transmission processing of the control signal generated by the control signal generation unit 311.

  Reference numeral 313 denotes a control signal antenna that transmits a control signal to the satellite (1) and the satellite (2).

  Reference numeral 314 denotes a SW01 / SW02 control unit that switches SW01 and SW02 at respective switching timings based on an instruction from the switching control unit 310.

  Reference numeral 315 denotes a SW11 control unit that switches SW11 at a switching timing based on an instruction from the switching control unit 310.

  Next, the operation of the satellite communication system according to the present embodiment will be described.

  The ground terminals 1 to n transmit signals in individual frequency bands (f1 to fn).

  When the satellite (1) 21 and the satellite (2) 22 are not near the meeting point, that is, when only the satellite (1) 21 provides communication service, the satellite (1) 21 is connected via the input antenna 230. The signals 101, 103, and 105 of the ground terminals 1 to n are received and multiplexed in the frequency bands f1 to fn to be a signal 107 (FIG. 5). At this time, the SW 2111 of the satellite (1) is ON, the frequency is converted by the converter 2112 and becomes the signal 109 of the frequency band F1 ′ to Fn ′ (FIG. 6), and the earth is output from the output antenna 250. It is transmitted to the station 30.

  Next, when the satellite (1) 21 and the satellite (2) 22 reach the vicinity of the meeting point, the switching control unit 310 of the earth station 30 causes the satellite (1) 21 and the satellite (2) 22 to be near the meeting point. Is detected. After detecting that the satellite (1) and the satellite (2) are in the vicinity of the meeting point, the switching control unit 310 switches the SW 2111 OFF timing of the satellite (1) 21 and the ON timing of the SW 2211 of the satellite (2) 22. , SW01 switching timing, SW02 switching timing, and SW11 switching timing are sequentially determined as the handover process progresses.

  Based on an instruction from the switching control unit 310, a control signal (an SW2111 OFF signal and an SW2211 ON signal) is generated from the control signal generation unit 311, and the satellite is transmitted via the control signal transmission unit 312 and the control signal antenna 313. A control signal is transmitted to (1) 21 and satellite (2) 22.

  In the satellite (1) and the satellite (2), the SW control unit receives the control signal via the control signal antenna and the control signal receiving unit, respectively, and controls the SW in the internal circuit according to the control signal.

  Specifically, as shown in FIG. 2, the earth station 30 transmits an ON signal to the SW 2211 in the satellite (2) 22, and the SW 2211 is turned ON to transmit the signal 202 in the frequency band F1 ″ to Fn ″. After the predetermined period has elapsed, an OFF signal is transmitted to the SW 2111 of the satellite (1) 21 to stop signal transmission from the satellite (1) 21.

  In the earth station 30, the signal from the satellite (1) is received, and the SW01 / SW02 control unit 314 turns on SW02 in response to the ON timing of the SW 2211 of the satellite (2) 22, and the signal from the satellite (2) 22 is received. The reception of 202 is started.

  For a while after the signal reception from the satellite (2) 22 is started, the SW 11 is on the delay unit 307 side (satellite (1) side), and the signal from the satellite (1) is information data (communication devices 40 to 40). Output signal to 60). Thereafter, after a predetermined time has elapsed, the switching control unit 310 instructs switching of the SW11, and the SW11 control unit 315 switches SW11 to the delay unit 308 side (satellite (2) side) based on the instruction from the switching control unit 310. The signal from the satellite (2) is used as information data.

  Thus, in the satellite communication system according to the present embodiment, when the satellite (1) and the satellite (2) reach the vicinity of the meeting point, the same signal is received from both the satellite (1) and the satellite (2). Are overlapped in parallel for a certain time, and a plurality of channels of signals are collectively handed over between the satellite (1) and the satellite (2).

  In the satellite communication system according to the present embodiment, the signal reception from the satellite (1) and the signal reception from the satellite (2) are performed in different frequency bands, so that errors due to radio wave interference and the like are avoided. be able to.

  In the above description, the signal reception from the satellite (1) and the signal reception from the satellite (2) are performed in parallel for a certain period of time, but simultaneously with the start of signal reception from the satellite (2). The signal reception from the satellite (1) may be stopped and the handover may be performed.

Embodiment 2. FIG.
The system shown in the first embodiment uses F1 ′ to Fn ′ for signal reception from the satellite (1), and uses the frequency band F1 ″ to Fn ″ for signal reception from the satellite (2). . However, the frequency band F1 ″ to Fn ″ used for signal reception from the satellite (2) is not used before the handover, and F1 ′ to Fn ′ used for signal reception from the satellite (1) after the handover. Therefore, there is an aspect that effective use of the frequency band cannot be achieved.

  Therefore, in the present embodiment, a system that improves the system of the first embodiment and can efficiently use finite frequency resources will be described.

  The overall configuration diagram of the satellite communication system according to the present embodiment is substantially the same as that shown in FIG. However, in the present embodiment, the frequency band of the signal 201 transmitted from the satellite (1) 21 to the earth station 30 and the frequency band of the signal 202 transmitted from the satellite (2) 22 to the earth station 30 are shown in FIG. It is different from the one. This point will be described in detail later.

  FIG. 7 shows an internal configuration example of the satellite (1) and the satellite (2) of the present embodiment.

  In FIG. 7, internal circuits (1) to (n) are arranged in the satellite communication device (1) 210 of the satellite (1) 21, and the internal circuit (1) is also arranged in the satellite communication device (2) 220 of the satellite (2) 22. ) To (n) are arranged.

  Each internal circuit includes a SW (switch), a BPF (band pass filter), and a converter.

  The BPF performs band limitation on the signal 107 (108) for n channels, and can extract information for one specific channel from the n channels. In addition, the BPF 1 to n in the satellite communication device (1) 210 take out information of different channels (frequency bands). For example, BPF1 (2152) extracts only the Ch1 signal in the frequency band f1 from the frequency bands f1 to fn, and BPF2 (2162) extracts only the Ch2 signal in the frequency band f2.

  The BPF in the satellite communication device (2) 220 corresponds to the BPF of the satellite communication device (1) 210. For example, the BPF 1 (2152) of the satellite communication device (1) 210 and the satellite communication device (2). 220 BPF1 (2252) both extract Ch1 signal in frequency band f1, and BPFn (2172) in satellite communication device (1) 210 and BPFn (2272) in satellite communication device (2) 220 both are Chn signals in frequency band fn. Take out.

  Here, the processing of the BPF and the converter will be described with reference to FIG.

  Here, as an example, processing of the BPF1 (2152), the converter 1 (2153), the BPF2 (2162), and the converter 2 (2163) of the satellite communication device (1) will be described.

  BPF1 (2152) takes out the Ch1 signal of frequency band f1 from the n-channel signals of frequency bands f1 to f, and converter 1 (2153) converts it into F2 which is a frequency band different from f1. The signal 111 is output. BPF2 (2162) takes out Ch2 signal in frequency band f2 from n-channel signals in frequency bands f1 to f, and converter 2 (2163) converts it to F3, which is a frequency band different from f2. The Ch2 signal 112 is output.

  Next, the relationship between the converter of the satellite communication device (1) 210 and the converter of the satellite communication device (2) 220 will be described with reference to FIG.

  As described in FIG. 9, the converter 1 (2153) of the satellite communication device (1) 210 converts the frequency of the Ch1 signal of f1 to output the Ch1 signal 111 of the frequency band F2, and the converter 2 (2163). Converts the frequency of the Ch2 signal of f2 and outputs the Ch2 signal 112 of the frequency band F3. On the other hand, the converter 1 (2253) of the satellite communication device (2) receives the Ch1 signal of the frequency band f1, converts this signal into the frequency band F1, and outputs the Ch1 signal 211, and the converter 2 (2263). Inputs the Ch2 signal in the frequency band f2, converts this signal into the frequency band F2, and outputs the Ch2 signal 112.

  Thus, the frequency band F2 of the output signal of the converter 1 (2153) of the satellite communication device (1) 210 matches the frequency band F2 of the output signal of the converter 2 (2263) of the satellite communication device (2) 220. It has become a relationship. Similarly, in other converters, the frequency of the output signal matches between the converter n-1 of the satellite communication device (1) 210 and the converter n of the satellite communication device (2) 220. ing.

  As a result, the output signal from the satellite (1) is in the frequency band F2 to Fn + 1, and the output signal from the satellite (2) is in the frequency band F1 to Fn.

  Next, an internal configuration example of the earth station 30 according to the present embodiment will be described with reference to FIG.

  In FIG. 8, reference numeral 317 denotes a distributor (1) that is connected to the antenna (1) 301 and distributes a signal from the antenna (1) 301. Reference numeral 318 denotes a distributor (2) that is connected to the antenna (2) 302 and distributes a signal from the antenna (2) 302.

  Reference numeral 340 denotes a switch 0 connected to the distributor (1) 317 and the distributor (2) 318. In the switch 0 (340), switches SW01 to SW0n + 1 are arranged.

  Reference numerals 321a to 321n + 1 denote BPFs (band pass filters), which are connected to corresponding switches among SW01 to SW0n + 1, respectively. The BPFs 321a to 321n + 1 extract signals in a specific frequency band from the signals in the frequency bands F2 to Fn + 1 from the satellite (1) and the signals in the frequency bands F1 to Fn from the satellite (2). For example, the BPF 321a extracts a signal in the frequency band F1.

  Reference numerals 322a to 322n + 1 denote demodulators that perform demodulation processing on the signals extracted by the BPFs 321a to 321n + 1.

  323a to 323n + 1 are delay units, and the delay time from the ground terminal → satellite (1) → switch 1 (324) is the same as the delay time from the ground terminal → satellite (2) → switch 1 (324). Adjust as follows.

  Reference numeral 324 denotes a switch 1 that outputs either the satellite (1) signal or the satellite (2) signal as information data (output signal to the communication devices 40 to 60) by switching. In the switch 1 (324), SW11 to SW1n are arranged.

  Reference numeral 325 denotes an SW0 control unit that controls SW01 to SW0n + 1 arranged in the switch 0 (340).

  Reference numeral 326 denotes an SW1 control unit that controls SW11 to SW1n arranged in the switch 1 (324).

  The other elements are the same as those shown in FIG.

  Next, the operation will be described.

  Before the satellite (1) and the satellite (2) reach the vicinity of the meeting point, SW1 (2151) to SWn (2171) of the satellite communication device (1) 210 are all ON, and the satellite communication device (2) 220 SW1 (2251) to SWn (2271) are all OFF. For this reason, no signal is transmitted from the satellite (2), and signals in the frequency band of F2 to Fn + 1 (channels 1 to n) are transmitted from the satellite (1) 21. In the switch 0 (340) of the earth station 30, SW02 to SW0n + 1 are on the distributor (1) 317 side (satellite (1) side) and receive a signal from the satellite (1) (FIG. 8).

  When the satellite (1) and the satellite (2) reach the vicinity of the meeting point, both the satellite communication device (1) and the satellite communication device (2) use the SW control unit based on the control signal from the earth station 30. Switch the SW. Here, an example of SW switching based on a control signal (in the case of a pulse signal) and a state of signal reception at the earth station 30 will be described with reference to FIGS. 11 and 12.

  First, an ON signal for SW1 (2251) of the internal circuit (1) of the satellite (2) 22 is issued from the switching control unit 310 of the earth station 30, and the control signal receiving unit 222 of the satellite (2) 22 receives this control signal. The SW control unit 223 switches SW1 (2251) of the internal circuit (1) to ON (S111, S121). Thereby, the BPF1 (2252) of the internal circuit (1) extracts the Ch1 signal of f1 from the n-channel signals of the frequency bands f1 to fn, and the converter 1 (2253) converts this signal into the Ch1 signal of the frequency band F1. And output from the output antenna 260.

  In the earth station 30, the SW0 control unit 326 switches SW01 of the switch 0 (340) to the distributor (2) 318 side (satellite) in response to transmission of the ON signal to SW1 of the internal circuit (1) of the satellite (2) 22. (2) side) and receive the Ch1 signal from the satellite (2) in the frequency band F1. On the other hand, SW02 has been on the distributor (1) 317 side (satellite (1) side) before the handover is started, and receives the Ch1 signal from the satellite (1) in the frequency band F2. Therefore, during the period P1 in FIG. 12, the earth station 30 transmits the Ch1 signal (via SW01) in the frequency band F1 transmitted from the satellite (2) and the Ch1 signal in the frequency band F2 transmitted from the satellite (1). Both are received (via SW02).

  Further, at a predetermined timing within this P1 period, the SW11 of the switch 1 (324) of the earth station 30 switches from the input from the delay unit 323b (signal from the satellite (1)) to the input from the delay unit 323a (satellite (2 ), And the signal from the satellite (2) is used as information data (output signal to the communication devices 40 to 60). This SW11 switching is performed by the SW0 control unit 326 based on the control from the switching control unit 310.

  Next, the switching control unit 310 of the earth station 30 issues an OFF signal for SW1 (2151) of the internal circuit (1) of the satellite (1), and the control signal receiving unit 212 receives the satellite (1), and SW The control unit 213 switches SW1 (2151) of the internal circuit (1) to OFF (S112, S122). Thereby, the input to the BPF1 (2152) of the satellite (1) is cut off, the signal transmission from the satellite (1) is stopped for the Ch1 signal, and the earth station 30 is also the signal from the satellite (1) for the Ch1 signal. Stop receiving. As a result, the handover for Ch1 is completed, the frequency band F2 used by the satellite (1) for transmitting the Ch1 signal is released, and this frequency band F2 becomes an empty frequency band.

  Next, after a predetermined guard time elapses, the switching control unit 310 of the earth station 30 issues an ON signal for SW2 (2261) of the internal circuit (2) of the satellite (2), and the satellite (2) receives a control signal. The reception unit 222 receives the signal, and the SW control unit 223 switches the SW2 of the internal circuit (2) to the ON state (S113, S123). Thereby, the BPF2 (2262) of the internal circuit (2) extracts the Ch2 signal of f2 from the n-channel signals of the frequency bands f1 to fn, and the converter 2 (2263) converts this signal into the Ch2 signal of the frequency band F2. And output from the output antenna 260. As described above, since the signal transmission from the satellite (1) is stopped, the frequency band F2 is an empty frequency band. The satellite (2) can transmit the Ch2 signal using F2 which is this vacant frequency band.

  In the earth station 30, the SW0 control unit 326 switches the SW02 of the switch 0 (340) to the distributor (2) 318 side (satellite) in response to the ON signal transmission to the SW2 of the internal circuit (2) of the satellite (2) 22. (2) side) and receive the Ch2 signal from the satellite (2) in the frequency band F2. On the other hand, SW03 has been on the distributor (1) 317 side (satellite (1) side) before the handover is started, and receives the Ch2 signal from the satellite (1) in the frequency band F3. Therefore, during the period P2 in FIG. 12, the earth station 30 transmits the Ch2 signal in the frequency band F2 (via SW02) transmitted from the satellite (2) and the Ch2 signal in the frequency band F3 transmitted from the satellite (1). (Via SW03).

  Further, at a predetermined timing within this P2 period, the SW 12 of the switch 1 (324) of the earth station 30 is switched from the input from the delay unit 323c (signal from the satellite (1)) to the input from the delay unit 323b (satellite (2 ), And the signal from the satellite (2) is used as information data (output signal to the communication devices 40 to 60). The switching of the SW 12 is performed by the SW 0 control unit 326 based on the control from the switching control unit 310.

  Thereafter, the switching control unit 310 of the earth station 30 issues an OFF signal for SW2 (2161) of the internal circuit (2) of the satellite (1), and the SW2 (2161) of the internal circuit (2) is transmitted to the satellite (1). Is switched to OFF (S113), the transmission of the Ch2 signal (frequency band F3) from the satellite (1) is stopped, and the frequency band F3 is released to make a free frequency band.

  Thereafter, the same processing is repeated using the vacant frequency band, switching to the Chn signal (Ch6 signal in FIG. 12) is performed, and the handover is completed for a plurality of channels.

  As described above, according to the satellite communication system according to the present embodiment, the handover is performed for each channel and the vacant frequency band is sequentially shifted to the adjacent frequency band to perform the handover. Resources can be used efficiently. Note that the vacant frequency band may be shifted at random instead of sequentially shifting to the next.

  The configuration may be different from the internal configuration example of the satellite (1) and the satellite (2) in FIG. For example, a converter may be inserted between the input antenna and the SW. An amplifier may be inserted between the output antenna and the converter. Further, the input antenna and the output antenna may be shared. There may be a plurality of input antennas and output antennas. Furthermore, the outputs from the internal circuits may be emitted from the output antenna without being combined. Further, the output of the BPF may be combined and received by one or a plurality of converters.

  In the above description, the case where the ON / OFF control signal is a pulse is taken as an example, but another signal such as a bilevel may be used to perform the ON / OFF control. Further, only the orbit information of the satellite can be transmitted from the earth station, and the ON / OFF control of the switch can be performed by the OBP (on-board processor) in the satellite.

  In the above description, the signal reception from the satellite (1) and the signal reception from the satellite (2) are performed in parallel for a certain period of time. However, simultaneously with the start of the signal reception from the satellite (2). The signal reception from the satellite (1) may be stopped and handed over.

Embodiment 3 FIG.
In the second embodiment, the satellite BPF (band pass filter) extracts a signal for one channel from an n-channel signal, but in this embodiment, one BPF extracts a signal for a plurality of channels. The case will be described.

  FIG. 13 is a diagram for explaining the operation of the satellite communication system according to the present embodiment.

  FIG. 13 illustrates an operation in which the BPF1 (2152) of the internal circuit (1) of the satellite (1) 21 and the BPF2 (2162) of the internal circuit (2) take out signals of a plurality of channels.

  BPF1 (2152) takes out the signals of two channels of f1 and f2 out of the n-channel signals of f1 to fn as one group, and BPF2 (2162) takes the signals of two channels of f3 and f4 as one. Take out as a group.

  Each BPF in the satellite (1) takes out signals of individual frequency bands, and the frequency bands do not overlap. As for the satellite (2), the BPF in the satellite (2) takes out signals of individual frequency bands, and the frequency bands do not overlap. The BPFs corresponding to each other of the satellite (1) and the satellite (2) have the same characteristics and realize the same band control. For example, both the BPF1 of the satellite (1) and the BPF1 of the satellite (2) take out signals for two channels f1 and f2 as one group.

  When the input signals 107 and 108 are signals having information for n channels, the number of internal circuits mounted on the satellite (1) 21 and the satellite (2) 22 may be m. However, it is desirable that n> m, and n is a number divisible by m.

  The relationship between the frequency and time of the signal received by the earth station in the present embodiment is as shown in FIG. 14, and the handover time can be shortened compared to the second embodiment, and the circuit mounted on the satellite Can be reduced.

Embodiment 4 FIG.
In the present embodiment, a local oscillator capable of supporting two types of frequencies is provided in each of the converter of the satellite communication device (1) and the converter of the satellite communication device (2) shown in FIG. A case where appropriate switching control is performed will be described.

  In this embodiment, the frequency of the output signal from the converter can be changed by changing the frequency of the local oscillator.

  FIG. 15 shows the operation of the converter according to the present embodiment, and shows the operation of converter 1 (2153) and converter 2 (2163) of satellite (1).

  In the converter 1 (2153), the two frequencies of the local oscillator are F1 and F2, and the Ch1 signal of the frequency f1 extracted by the BPF1 can be converted into either the signal of the frequency F1 or the signal of F2. In the converter 2 (2163), the two frequencies of the local oscillator are F2 and F3, and the Ch2 signal of the frequency f2 extracted by the BPF2 can be converted into either the signal of the frequency F2 or the signal of F3. .

  The converters in the satellite (1) correspond to two individual frequencies, and the frequency bands do not overlap. As for the satellite (2), the converters in the satellite (2) correspond to two separate frequencies, and the frequency bands do not overlap. The converters corresponding to each other of the satellite (1) and the satellite (2) have the same characteristics, and two frequencies that can oscillate are common. For example, both the converter 1 of the satellite (1) and the converter 2 of the satellite (2) can correspond to the frequencies F1 and F2.

  When the frequency band of the signal received from the earth station 30 before the handover (the signal from the satellite (1) 21) is F2 to Fn + 1 as shown in FIG. 16, it is shown in the second embodiment. As described above, the output frequency of the satellite (2) 22 must be F1 to Fn. For this reason, the frequency of the local oscillator of the converters (2253, 2263, 2273) in the satellite (2) is set so that the output frequency of the satellite (2) 22 is F1 to Fn. The handover at this time is performed by a method similar to the method shown in the second embodiment.

  When the frequency band of the signal received from the earth station 30 before the handover (signal from the satellite (1) 21) is F1 to Fn as shown in FIG. 17, the satellite (2) 22 The frequency of the local oscillator of the converter (2253, 2263, 2273) in the satellite (2) is set so that the output frequency of F2 is F2 to Fn + 1. In this case, contrary to the second embodiment, the switches are turned ON / OFF in the order from the internal circuit (n) to the internal circuit (1). In this case, the relationship between the frequency and time of the signal received by the earth station is as shown in FIG.

  The frequency switching of the transducer local oscillator is controlled by sending a signal from the earth station. Further, only the orbit information of the satellite may be transmitted from the earth station, and the control may be performed by an OBP (on-board processor) in the satellite.

  According to the present embodiment, when there are a plurality of satellites in orbit and the handover is performed many times, the signal received by the earth station is in the state shown in FIG. 12 or FIG. Therefore, frequency resources can be used efficiently by utilizing an empty frequency band.

Embodiment 5 FIG.
In the first to fourth embodiments described above, the handover in the case where the signal transmitted from the ground terminal is transmitted from the satellite to the earth station has been described. In this embodiment, the signal from the earth station to the satellite is described. Will be described.

  In the present embodiment, a handover will be described in the case where a signal is transmitted from the earth station to the satellite with the same configuration as that shown in the first embodiment.

  FIG. 19 shows an internal configuration example of the earth station according to the present embodiment.

  19, reference numerals 301 to 304, 307, 308, 310 to 314 are the same as those shown in FIG.

  Reference numeral 333 denotes a HYB (hybrid) that distributes the information data transmitted from the communication devices 40 to 60 to SW11 (319) and SW12 (320).

  Reference numeral 319 denotes a SW (switch) 11, and reference numeral 320 denotes a SW (switch) 12. SW11 (319) performs ON / OFF switching between the HYB 333 and the delay unit 307, and SW12 (320) performs ON / OFF switching between the HYB 333 and the delay unit 308.

  Reference numerals 327 and 328 denote modulators that perform modulation processing. The modulator 327 modulates a signal to the satellite (1), and the modulator 328 modulates a signal to the satellite (2).

  In FIG. 19, the antenna (1) 301 is directed to the satellite (1) and transmits a signal 201 to the satellite (1). The signal 201 to the satellite (1) includes signals for n channels and is transmitted in the frequency band F1 'to Fn'. The antenna (2) 302 is directed to the satellite (2) and transmits a signal 202 to the satellite (2). The signal 202 to the satellite (2) includes signals for n channels and is transmitted in the frequency band of F1 ″ to Fn ″. The signal 201 to the satellite (1) and the signal 202 to the satellite (2) have the same signal content.

  FIG. 20 shows an example of the internal configuration of the satellite according to the present embodiment.

  Regarding the satellite (1) 21, 251 is an input antenna that receives the signal 201 from the earth station, and 231 is an output antenna that transmits the signals 101, 103, and 105 to the ground terminals 1 to n.

  Reference numeral 218 denotes an internal circuit that performs frequency conversion on the signal 201 (frequency bands F1 'to Fn') received by the input antenna 251 and outputs a signal in the frequency band of f1 to fn to the output antenna 231. The internal circuit 218 includes a SW (switch) 2181 and a converter 2182. The converter 2182 receives signals in the frequency bands F1 'to Fn', performs frequency conversion, and outputs signals in the frequency bands f1 to fn.

  The satellite (2) has the same configuration as that of the satellite (1), but the converter 2282 receives signals in the frequency bands F1 ″ to Fn ″ and performs frequency conversion to convert the frequency bands f1 to f1. The signal of fn is output.

  The satellite (1) and the satellite (2) transmit signals for n channels to all the ground terminals 1 to n. Specifically, the Ch1 signal of channel 1 is transmitted to all the ground terminals 1 to n in the frequency band f1, and then the Ch2 signal of channel 2 is directed to all the ground terminals 1 to n in the frequency band f2. To send. Each of the ground terminals 1 to n receives a corresponding signal using a unique reception frequency. During the handover process, the same signal is transmitted in duplicate in the same frequency band from the satellite (1) and the satellite (2), but each ground terminal can receive an appropriate signal by adaptive equalization.

  Next, the operation of the satellite communication system according to the present embodiment will be described.

  When the satellite (1) 21 and the satellite (2) 22 are not in the vicinity of the meeting point, that is, when only the satellite (1) 21 is performing a communication service, the earth station 30 has SW11 (319) and SW01 (303). ) Is turned ON, and an n-channel signal 201 in the frequency bands F1 ′ to Fn ′ is transmitted from the antenna (1) 301 to the satellite (1). At this time, SW12 (320) and SW02 (304) of the earth station 30 are OFF. In the satellite (1), the SW 2181 of the internal circuit 218 is ON, the frequency is converted by the converter 2182, and the signals 101, 105, 103 of the frequency bands f1 to fn are output from the output antenna 231 to the ground terminals 1 to 1. sent to n.

  Next, when the satellite (1) 21 and the satellite (2) 22 reach the vicinity of the meeting point, the switching control unit 310 of the earth station 30 causes the satellite (1) 21 and the satellite (2) 22 to be near the meeting point. Is detected. After detecting that the satellite (1) and the satellite (2) are in the vicinity of the meeting point, the switching control unit 310 detects the SW OFF timing of the satellite (1) 21 and the SW 2 ON timing of the satellite (2) 22. , SW01 switching timing, SW02 switching timing, SW11, SW12 switching timing, etc. are sequentially determined along with the progress of the handover process.

  Based on an instruction from the switching control unit 310, the SW11 / SW12 control unit 329 turns on SW12 (320), and the SW01 / SW02 control unit 314 turns on SW02. Accordingly, the n-channel signal 202 in the frequency bands F1 ″ to Fn ″ is transmitted from the antenna (2) 302 to the satellite (2).

  In parallel with this, based on an instruction from the switching control unit 310, the control signal generation unit 311 generates an ON signal for the SW 2281 of the satellite (2), and the control signal transmission unit 312 sends the ON signal from the control signal antenna 313. Send.

  In the satellite (2), based on the ON signal from the earth station 30, the SW 2281 is turned on, and the converter 2282 performs frequency conversion on the signal 202 in the frequency bands F1 ″ to Fn ″, and the frequency band f1 to f1. The signals 102, 104, and 106 of fn are transmitted to the ground terminals 1 to n.

  Then, in the earth station 30, after the signal is transmitted to the satellite (1) and the satellite (2) redundantly for a predetermined period, the SW11 / SW12 control unit 329 turns off SW11 (319), and SW01 The / SW02 control unit 314 turns off SW01 (303) and stops signal transmission to the satellite (1).

  In parallel, the control signal generation unit 311 generates an OFF signal for the SW 2181 of the satellite (1), and the control signal transmission unit 312 transmits the OFF signal from the control signal antenna 313.

  In the satellite (1), based on the OFF signal from the earth station 30, the SW 2181 is turned OFF and the signal transmission to the ground terminals 1 to n is stopped.

  With the above procedure, handover is completed for signals of a plurality of channels. The relationship between the frequency band and time of the signal transmitted from the earth station 30 to the satellite (1) and the satellite (2) is as shown in FIG.

  In the ground terminals 10a to 10n, the satellite (1) and the satellite (2) are almost in the same position (because they are at the meeting point), so the satellite (1) was switched to the satellite (2) without moving the antenna. You can continue to receive data. After the handover, the antennas of the ground terminals 10a to 10n track the satellite (2). The ground terminals 10a to 10n repeatedly receive the same signal from the satellite (1) and the satellite (2) in parallel in the same frequency band for a certain period of time. However, since they are low bit rate signals, the timings of both signals are received. The shift is small, and there is no problem even if the same frequency band is received in duplicate.

  Thus, in the satellite communication system according to the present embodiment, when the satellite (1) and the satellite (2) reach the vicinity of the meeting point, the same for both the satellite (1) and the satellite (2). Signals are transmitted in parallel for a certain period of time, and a plurality of channels of signals are collectively handed over between the satellite (1) and the satellite (2).

  In the satellite communication system according to the present embodiment, signal transmission to the satellite (1) and signal transmission to the satellite (2) are performed in different frequency bands, so that errors due to radio wave interference and the like are avoided. be able to.

  In the above description, the signal transmission to the satellite (1) and the signal transmission to the satellite (2) are performed in parallel for a certain time, but the start of signal transmission to the satellite (2) At the same time, signal transmission to the satellite (1) may be stopped and handed over.

  Note that the configuration shown in Embodiment 1 and the configuration shown in Embodiment 5 may be combined to form a satellite capable of bidirectional transmission and reception with the earth station. Alternatively, the configuration shown in Embodiment 1 and the configuration shown in Embodiment 5 may be combined to form an earth station capable of bidirectional transmission and reception with a satellite.

Embodiment 6 FIG.
In the present embodiment, a case will be described in which a signal is transmitted from an earth station to a satellite, and handover is performed using a vacant frequency band as in the second embodiment.

  FIG. 22 shows an internal configuration example of the earth station 30 according to the present embodiment.

  In the configuration of FIG. 22, the demodulators 322a to 322n + 1 in FIG. 8 are replaced with the modulators 330a to 330n + 1, and the distributor (1) 317 and the distributor (2) 318 are combined with the combiner (1) 331 and the combiner (2) 332. The configuration is substantially the same as that of FIG. 8 except that the direction of the signal is reversed.

  FIG. 23 shows an internal configuration example of the satellite (1) 21 and the satellite (22) according to the present embodiment.

  Since the direction of the signal is reversed, the positions of the input antenna and the output antenna for both the satellite (1) and the satellite (2) are reversed from the configuration of FIG. 7, and the positions of the SW and the converter in the internal circuit Is the reverse of the configuration of FIG. Except for these points, the configuration is almost the same as that of FIG.

  Next, the operation of the satellite communication system according to the present embodiment will be described.

  Before the satellite (1) and the satellite (2) reach the vicinity of the meeting point, the switch 0 (340) and the switch 1 (324) of the earth station 30 are in the state shown in FIG. A signal in the frequency band of F2 to Fn + 1 is transmitted from the satellite 301 to the satellite (1), and no signal is transmitted to the satellite (2). In addition, SW1 (2333) to SWn (2353) of the satellite communication device (1) 210 are all ON, and SW1 (2433) to SWn (2453) of the satellite communication device (2) 220 are all OFF. For this reason, the satellite (1) receives the signals F2 to Fn + 1, performs frequency conversion, and transmits the signals f1 to fn to the ground terminals 1 to n.

  Next, when the satellite (1) 21 and the satellite (2) 22 reach the vicinity of the meeting point, the switching control unit 310 of the earth station 30 causes the satellite (1) 21 and the satellite (2) 22 to be near the meeting point. Is detected. After detecting that the satellite (1) and the satellite (2) are in the vicinity of the meeting point, the switching control unit 310 switches the SW1 to SWn OFF timing of the satellite (1) 21 and the SW1 to SW1 of the satellite (2) 22. SWn ON timing, switch 0 switching timing, switch 1 switching timing, etc. are sequentially determined as the handover process progresses, and switch switching control in the earth station 30, satellite (1) and satellite (2) is performed. Do.

  Hereinafter, the switch switching example and the content of the transmission signal from the earth station 30 will be described with reference to FIG.

  First, in the earth station 30, the SW1 control unit 326 turns on SW11 of the switch 1 (324), and the SW0 control unit 325 sets SW01 of the switch 0 (340) to the distributor (2) 318 side (satellite (2) side). (S241). Accordingly, the Ch1 signal is transmitted from the antenna (2) 302 to the satellite (2) in the frequency band F1.

  In parallel, the switching control unit 310 issues an ON signal to SW1 (2433) of the internal circuit (1) of the satellite (2) 22, and the control signal receiving unit 222 of the satellite (2) 22 transmits this control signal. The SW control unit 223 switches SW1 (2433) of the internal circuit (1) to the ON state. As a result, the satellite (2) 22 receives the Ch1 signal in the frequency band F1, performs frequency conversion by the converter 2431 in the internal circuit (1) 243, and transmits the Ch1 signal in the frequency band f1 from the output antenna.

  During the period of P1, the earth station transmits a Ch1 signal in the frequency band F2 (via SW02) to the satellite (1) and transmits a Ch1 signal in the frequency band F1 (via SW01) to the satellite (2). doing.

  Thereafter, the earth station 30 sets SW01 of the switch 0 to an intermediate state (a state that is neither the synthesizer (1) side nor the synthesizer (2) side), and stops the transmission of the Ch1 signal to the satellite (1) (S241). . In parallel with this, the earth station 30 transmits an OFF signal to SW1 of the satellite (1), and the satellite (1) turns off SW1 and stops receiving the Ch1 signal. In the earth station 30, since the signal transmission to the satellite (1) is stopped, the frequency band F2 is released as an empty frequency band, and F2 which is this empty frequency band can be used for signal transmission to the satellite (2).

  After the elapse of a predetermined guard time, in the earth station 30, SW02 of switch 0 is set to the synthesizer (2) 332 side (satellite (2) side), and SW12 of switch 1 is set to the HYB 333b side of information data 2 (Ch2). (S241). As a result, the Ch2 signal is transmitted to the satellite (2) in the frequency band F2, which is an empty frequency band (via SW02). In this way, during the period P2, the earth station transmits the Ch2 signal in the frequency band F3 (via SW03) to the satellite (1) and the Ch2 signal in the frequency band F2 (via SW02) to the satellite (2). ) Is then transmitted, the transmission of the Ch2 signal to the satellite (1) is stopped, and the frequency band F3 used for the transmission of the Ch2 signal to the satellite (1) is released as a free frequency band.

  Thereafter, similar processing is repeated using the vacant frequency band, switching is performed up to the Chn signal (Ch6 signal in FIG. 24), and handover is completed for a plurality of channels.

  As described above, according to the satellite communication system according to the present embodiment, even in the signal transmission from the earth station to the satellite, the handover is performed for each channel, and the free frequency band is sequentially shifted to the adjacent frequency band. Since handover is performed, frequency resources that are limited can be used efficiently. Note that the vacant frequency band may be shifted at random instead of sequentially shifting to the next.

  Note that the processing shown in Embodiment 3 and the processing shown in Embodiment 4 may be applied to the satellite communication system shown in this embodiment.

  Further, the configuration shown in Embodiment 2 and the configuration shown in Embodiment 6 may be combined to form a satellite that can transmit and receive bidirectionally with the earth station. Alternatively, the configuration shown in Embodiment 2 and the configuration shown in Embodiment 6 may be combined to form an earth station capable of bidirectional transmission and reception with a satellite.

The figure which shows the example of whole structure of a satellite communication system. The figure which shows the received signal condition in the earth station which concerns on Embodiment 1. FIG. FIG. 3 is a diagram illustrating an internal configuration example of the satellite according to the first embodiment. FIG. 3 shows an internal configuration example of the earth station according to the first embodiment. FIG. 4 shows an operation of the input antenna of the satellite according to the first embodiment. FIG. 3 is a diagram showing an operation of the satellite converter according to the first embodiment. FIG. 5 is a diagram illustrating an internal configuration example of a satellite according to a second embodiment. The figure which shows the internal structural example of the earth station which concerns on Embodiment 2. FIG. The figure which shows operation | movement of the BPF and converter of the satellite which concerns on Embodiment 2. FIG. The figure which shows the relationship between the converter of the satellite (1) which concerns on Embodiment 2, and the converter of a satellite (2). The figure which shows the example of a timing of a control signal. The figure which shows the received signal condition in the earth station which concerns on Embodiment 2. FIG. The figure which shows operation | movement of BPF and the converter of the satellite which concerns on Embodiment 3. FIG. The figure which shows the received signal condition in the earth station which concerns on Embodiment 3. FIG. FIG. 10 shows an example of the operation of the satellite converter according to the fourth embodiment. The figure which shows the example of the signal which the earth station has received before the handover. The figure which shows the example of the signal which the earth station has received before the handover. The figure which shows the received signal condition of the earth station at the time of a handover. FIG. 10 is a diagram illustrating an internal configuration example of an earth station according to a fifth embodiment. FIG. 10 is a diagram illustrating an internal configuration example of a satellite according to a fifth embodiment. The figure which shows the transmission signal condition from the earth station which concerns on Embodiment 5. FIG. The figure which shows the internal structural example of the earth station which concerns on Embodiment 6. FIG. FIG. 10 shows an internal configuration example of a satellite according to a sixth embodiment. The figure which shows the transmission signal condition from the earth station which concerns on Embodiment 6. FIG. The figure explaining a quasi-zenith satellite. The figure explaining a quasi-zenith satellite.

Explanation of symbols

  10 ground terminals, 21 non-stationary satellites, 22 non-stationary satellites, 30 earth station devices, 40 communication devices, 50 communication devices, 60 communication devices.

Claims (7)

An earth station device capable of receiving signals from each of the first artificial satellite and the second artificial satellite,
While receiving a signal from the first artificial satellite, and switching the artificial satellite that receives the signal from the first artificial satellite to the second artificial satellite in a predetermined case,
A plurality of channels of signals can be received from each of the first satellite and the second satellite,
While receiving a signal of a plurality of channels from the first artificial satellite, in a predetermined case, the satellite that receives the signal is sequentially switched from the first artificial satellite to the second artificial satellite for each channel,
From the first satellite operating in a predetermined satellite orbit, it is possible to receive signals of multiple channels in individual frequency bands for each channel,
Correspondence of multiple channels corresponding to the signals of multiple channels transmitted by the first satellite from the second satellite operating on the satellite orbit different from the satellite orbit of the first artificial satellite and meeting with the first artificial satellite The signal can be received,
For a specific channel, start receiving the corresponding signal from the second artificial satellite in a predetermined frequency band and stop receiving the signal from the first artificial satellite to receive the signal of the corresponding channel. Switch from the artificial satellite to the second artificial satellite, open the frequency band used for signal reception from the first artificial satellite as an empty frequency band,
For the other channels, in sequence for each channel, start receiving the corresponding signal from the second artificial satellite in the free frequency band and stop receiving the signal from the first artificial satellite to receive the signal from the first artificial satellite. An earth station characterized in that a satellite that receives signals is switched from a first artificial satellite to a second artificial satellite for a plurality of channels by repeatedly releasing the frequency band used for the vacant frequency band. apparatus. An earth station device capable of transmitting a signal to each of the first artificial satellite and the second artificial satellite,
A signal is transmitted to the first artificial satellite and, in a predetermined case, the artificial satellite to which the signal is transmitted is switched from the first artificial satellite to the second artificial satellite,
A multi-channel signal can be transmitted to each of the first satellite and the second satellite,
A signal of a plurality of channels is transmitted to the first artificial satellite, and in a predetermined case, the artificial satellite to which the signal is transmitted is sequentially switched from the first artificial satellite to the second artificial satellite for each channel,
Multiple channel signals can be transmitted in individual frequency bands for each channel to the first satellite operating in a predetermined satellite orbit,
A second channel which associates a plurality of channels corresponding to a plurality of channels transmitted to the first satellite on a satellite orbit different from the satellite orbit of the first satellite and associates with the first satellite. Can be sent to
For a specific channel, transmission of the corresponding signal to the second artificial satellite is started in a predetermined frequency band, and signal transmission to the first artificial satellite is stopped, so that the artificial satellite to which the signal of the channel is transmitted is the first Switch from artificial satellite to second artificial satellite, open the frequency band used for signal transmission to the first artificial satellite as an empty frequency band,
For other channels, transmission of the corresponding signal to the second artificial satellite is started in the empty frequency band in order for each channel, and signal transmission to the first artificial satellite is stopped and used for signal transmission to the first artificial satellite. An earth station apparatus characterized in that a signal transmission destination artificial satellite is switched from a first artificial satellite to a second artificial satellite for a plurality of channels by repeating a process of releasing a designated frequency band as an empty frequency band . A satellite communication device that is mounted on an artificial satellite that operates on a predetermined satellite orbit and meets another artificial satellite, and that can transmit a signal to the earth station device,
Signals of multiple channels are transmitted to the earth station device in individual frequency bands for each channel, and in a predetermined case, signal transmission is stopped sequentially for each channel and the frequency band used for signal transmission is released as an empty frequency band. On board satellites that meet other satellites,
A multi-channel corresponding signal corresponding to a multi-channel signal transmitted by another artificial satellite can be transmitted to the earth station device,
For a specific channel, start transmission of a corresponding signal to the earth station device in a predetermined frequency band, and detect a free frequency band that is released when other artificial satellites stop signal transmission of the channel,
For other channels, in order for each channel, transmission of the corresponding signal to the earth station device is started in the detected vacant frequency band, and the vacant frequency band released when other artificial satellites stop signal transmission is detected. The satellite communication apparatus is characterized by starting the transmission of the corresponding signal for a plurality of channels by repeating the processing. A satellite communication device that is mounted on an artificial satellite that operates on a predetermined satellite orbit and meets another artificial satellite, and that can receive a signal from an earth station device,
Other signals that receive signals of multiple channels from the earth station device in individual frequency bands for each channel, stop signal reception for each channel in order, and open the frequency band used for signal reception as an empty frequency band On board satellites that meet with satellites,
A multi-channel corresponding signal corresponding to a multi-channel signal received by another artificial satellite can be received from the earth station device,
For a specific channel, start receiving a corresponding signal from the earth station device in a predetermined frequency band, and detect a free frequency band that has been released because other satellites stopped receiving the signal of the channel,
For other channels, in order for each channel, a process of starting reception of a corresponding signal from the earth station device in the detected vacant frequency band and detecting an vacant frequency band that has been released when other artificial satellites stopped receiving signals. The satellite communication apparatus is characterized by starting reception of corresponding signals for a plurality of channels. Connected to the earth station device that can receive signals from each of the first satellite and the second satellite, and transmitted from either the first satellite or the second satellite via the earth station device A communication device for receiving a signal,
While receiving a signal from the first artificial satellite and, in a predetermined case, via the earth station device that switches the artificial satellite that receives the signal from the first artificial satellite to the second artificial satellite,
Receiving a signal transmitted from either the first artificial satellite or the second artificial satellite;
The communication device is an earth station device,
It is possible to receive signals from multiple channels in the individual frequency band for each channel from the first satellite operating in the specified satellite orbit, and operate in a satellite orbit different from the satellite orbit of the first satellite. From a second satellite associated with one satellite, a corresponding signal of a plurality of channels corresponding to a signal of a plurality of channels transmitted by the first satellite can be received,
For a specific channel, start receiving the corresponding signal from the second artificial satellite in a predetermined frequency band and stop receiving the signal from the first artificial satellite to receive the signal of the corresponding channel. Switch from the artificial satellite to the second artificial satellite, open the frequency band used for signal reception from the first artificial satellite as an empty frequency band,
For the other channels, in sequence for each channel, start receiving the corresponding signal from the second artificial satellite in the free frequency band and stop receiving the signal from the first artificial satellite to receive the signal from the first artificial satellite. Through the process of releasing the frequency band used for the vacant frequency band, through an earth station device that switches the satellite that receives the signal from the first artificial satellite to the second artificial satellite for a plurality of channels,
A communication apparatus for receiving a signal transmitted from any one of a first artificial satellite and a second artificial satellite. A communication device capable of receiving signals from each of the first artificial satellite and the second artificial satellite,
While receiving a signal from the first artificial satellite, and switching the artificial satellite that receives the signal from the first artificial satellite to the second artificial satellite in a predetermined case,
A plurality of channels of signals can be received from each of the first satellite and the second satellite,
While receiving a signal of a plurality of channels from the first artificial satellite, in a predetermined case, the satellite that receives the signal is sequentially switched from the first artificial satellite to the second artificial satellite for each channel,
From the first satellite operating in a predetermined satellite orbit, it is possible to receive signals of multiple channels in individual frequency bands for each channel,
Correspondence of multiple channels corresponding to the signals of multiple channels transmitted by the first satellite from the second satellite operating on the satellite orbit different from the satellite orbit of the first artificial satellite and meeting with the first artificial satellite The signal can be received,
For a specific channel, start receiving the corresponding signal from the second artificial satellite in a predetermined frequency band and stop receiving the signal from the first artificial satellite to receive the signal of the corresponding channel. Switch from the artificial satellite to the second artificial satellite, open the frequency band used for signal reception from the first artificial satellite as an empty frequency band,
For the other channels, in sequence for each channel, start receiving the corresponding signal from the second artificial satellite in the free frequency band and stop receiving the signal from the first artificial satellite to receive the signal from the first artificial satellite. The communication apparatus is characterized in that the process of releasing the frequency band used in the above as a free frequency band is repeated to switch the satellite that receives signals for the plurality of channels from the first artificial satellite to the second artificial satellite. . Signals of multiple channels are transmitted to the earth station device in individual frequency bands for each channel, and in a predetermined case, signal transmission is stopped sequentially for each channel and the frequency band used for signal transmission is released as an empty frequency band. On board satellites that meet other satellites,
A multi-channel corresponding signal corresponding to a multi-channel signal transmitted by another artificial satellite can be transmitted to the earth station device,
For a specific channel, start transmission of a corresponding signal to the earth station device in a predetermined frequency band, and detect a free frequency band that is released when other artificial satellites stop signal transmission of the channel,
For other channels, in order for each channel, transmission of the corresponding signal to the earth station device is started in the detected vacant frequency band, and the vacant frequency band released when other artificial satellites stop signal transmission is detected. Is a satellite equipped with a satellite communication device characterized by starting transmission of corresponding signals for a plurality of channels, and operates on a predetermined satellite orbit and meets other satellites. A ground terminal that transmits signals of a plurality of channels to an artificial satellite.

Images