JP2016103733A - Satellite communication simulation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a satellite simulation system that uses a channel simulating an actual satellite communication channel and a delay time generation device, and thereby performs a communication function and system performance test in an environment equivalent to using the actual satellite communication channel without using a satellite communication channel.SOLUTION: A satellite communication simulation system 100 comprises: a pseudo satellite communication device 10 which is a weak radio station whose radio wave emission strength is set in a range stipulated by the radio wave law; and a master unit 20 and a slave unit 30 that perform both-way communication with each other via the pseudo satellite communication device 10. The master unit 20 comprises: a master unit antenna 21 for transmitting and receiving radio waves to/from the pseudo satellite communication device 10; a master unit control device 22 for controlling the transmission and reception of radio waves between the master unit antenna 21 and the pseudo satellite communication device 10; and a delay generation device 26 for reflecting a delay time occurring on an actual satellite communication channel in a simulation.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a simulation system for simulating a communication function of a bidirectional communication system via a communication satellite, and in particular, between a control base earth station, a portable mobile earth station, a small earth station, etc. via a communication satellite. The present invention relates to a satellite communication simulation system that simulates a communication function of a communication system between a control base earth station and a portable mobile earth station, a small earth station, or the like using a line imitating a satellite communication line when operating the communication system.

  As a two-way communication system via a communication satellite, VSAT (Very Small Aperture Terminal) is used for two-way communication between a control base earth station (hereinafter referred to as “HUB station”) and a small earth station (hereinafter referred to as “VSAT station”). Systems and fully automatic VSAT systems are known. Similarly, there is also known an ESV (Earth Stations on board Vessels) system for two-way communication between a HUB station and a portable mobile earth station (shipboard earth station) mounted on a ship (hereinafter referred to as an “ESV station”). ing. Note that these systems may be collectively referred to as “ESV system etc.”.

  Since equipment that constitutes an ESV system or the like requires advanced technology, when operating the system, it is essential to perform a communication function and system performance test with the HUB station. As described in Patent Document 1, it is performed using an actual communication satellite line.

JP 2000-332671 A

The communication function and system performance test with the HUB station are carried out using the above-mentioned actual communication satellite line, and the HUB station and the VSAT station or ESV station are connected by a coaxial cable, and the communication satellite and the HUB station are connected. In some cases, a signal such as a high-frequency IF frequency from a VSAT station or an ESV station is used. Alternatively, it may be performed while actually operating the system.
In the communication function and system performance test with the HUB station by these methods, there are the following problems.
When performing the test using an actual communication satellite line,
(1) Under the Radio Law, it is necessary to obtain a license for opening a radio station or the like in advance.
(2) It is necessary to allocate a part of the bandwidth of the expensive satellite communication line to the test, which impairs the efficient use of the satellite communication line.
(3) Since the system operation has not been confirmed, erroneous emission of radio waves at the initial stage of the test (for example, connection to a satellite other than the designated satellite, setting of frequency, modulation method, bandwidth, transmission power, transmission polarization plane) The occurrence of interference with other satellite operators due to mistakes cannot be prevented.
(4) Since there is a risk of the interference, it is not possible to perform an environmental test (sway (vibration) / running movement) of the ESV system or the like.
There is a problem in the quality control of the system.

Further, when the HUB station and the VSAT station or ESV station are connected by a coaxial cable and the test is performed using a signal such as a high-frequency IF frequency from a communication satellite, HUB station, VSAT station or ESV station,
(1) The confirmation test related to the antenna (antenna) system device cannot be performed, and the system test cannot be realized.
(2) When connecting a HUB station and a plurality of VSAT stations or ESV stations, a large number of mixers and distributors must be used, which makes wiring complicated and impractical.
(3) Since the overall system operation cannot be confirmed, erroneous emission of radio waves at the initial stage of the test (for example, connection to a satellite other than the designated satellite, frequency / modulation method / bandwidth / transmission power / transmission polarization plane setting error) ) Cannot interfere with other satellite operators.
(4) Since there is a risk of the interference, it is not possible to perform an environmental test (sway (vibration) / running movement) of the ESV system or the like.
There is a problem in the quality control of the system.

  Therefore, in the present invention, in order to solve the above-mentioned problems caused by performing the test by using an actual satellite communication line or connecting a HUB station and an ESV station by a coaxial cable, a communication satellite is used. It is an object to provide a satellite communication simulation system using a simulated pseudo satellite communication device.

In the present application, a control base earth station used in the satellite communication simulation system 100 according to the present invention is a master unit 20, and a mobile station such as a VAST station and an ESV station that can move and bidirectionally communicate with the master unit 20 is a slave unit 30.
In addition, the control base earth station installed on the earth that performs two-way communication using an actual satellite communication line is the HUB station 70, and the two-way communication with the HUB station 70 is possible such as a VAST station and an ESV station. The station is a slave station 80.
(First invention)
A first invention of the present application is a satellite communication simulation system 100 that simulates a communication function of a bidirectional communication system between a HUB station 70 and a slave station 80 via a communication satellite,
The satellite communication simulation system 100 includes:
A pseudo-satellite communication device 10 that is a weak radio station set within a range stipulated by the Radio Law, and a parent device 20 and a slave device 30 that perform bidirectional communication via the pseudo-satellite communication device 10, With
The pseudo satellite communication device 10 includes:
The antenna 11 that transmits and receives radio waves between the master unit 20 and the slave unit 30 and the radio waves emitted from the master unit 20 or the slave unit 30 are received, and the frequency of the received radio wave is converted to a predetermined frequency. A frequency converter 14;
The master 20 is
A base antenna 21 for transmitting and receiving radio waves to and from the antenna 11,
A base unit control device 22 for controlling transmission and reception of radio waves between the base unit antenna 21 and the antenna 11;
And a delay generator 26 for reflecting the delay time generated in the actual satellite communication line in the simulation.

  Here, the delay time is a radio wave propagation delay caused by a propagation distance when the HUB station 70 and the ESV station 80 communicate with an artificial satellite or the like on a geostationary satellite orbit. Since the delay time is determined by the propagation distance of radio waves, the delay time can be obtained by setting the target communication satellite. In other words, the delay time is a fixed value that can be set at the time of simulation, and by setting the delay time and reflecting the delay time in the simulation by the delay generator 26 provided in the master unit, the actual communication satellite and Various functions and performance tests can be performed in consideration of the distance.

(Second invention)
According to a second invention of the present application, in addition to the first invention, the frequency converter 14 has a frequency level adjustment function in which the master unit 20 and the slave unit 30 receive a downlink signal emitted from the communication satellite. It is characterized by having.
(Third invention)
The third invention of the present application is characterized in that, in addition to the first or second invention, the child device 30 includes an antenna control device 35 which is a GPS simulator for simulating the moving state of the child device 30. .

(Fourth invention)
4th invention of this application is the main | base station 20 which transmits / receives a radio | wireless with the pseudo | simulation satellite communication apparatus 10 which is the weak radio station set in the range which the radio wave emission intensity | strength is prescribed | regulated by the Radio Law,
Perform bidirectional communication with the slave unit 30 via the pseudo satellite communication device 10,
A base antenna 21 for transmitting and receiving radio waves to and from the pseudo satellite communication device 10, and
A master control device 22 for controlling transmission / reception of radio waves between the master antenna 21 and the pseudo satellite communication device 10,
And a delay generator 26 for reflecting the delay time generated in the actual satellite communication line to the bidirectional communication with the slave unit 30.

According to the present invention, a pseudo satellite communication apparatus which is a weak radio station as a communication satellite for performing a communication function test and system performance test such as an ESV system in which two-way communication is performed between a HUB station and an ESV station via a communication satellite. By using the master unit and the slave unit, it can be provided at a bench test level in an indoor space such as in a factory, and thus has the following effects.
(Effect in 1st invention)
According to the first invention, the use of the pseudo satellite communication device has the following effects.
(1) Various functions and performance tests of the HUB station and the slave station can be performed in an environment equivalent to using an actual satellite communication line.
(2) Since a weak radio station is used, it is not necessary to obtain a license for opening a radio station or the like in advance.
(3) It is not necessary to allocate a part of the band of the expensive satellite communication line to the test, and the efficient use of the satellite communication line is not impaired.
(4) Since various tests can be performed by freely changing the line parameters without using a part of the bandwidth of the satellite communication line, it is possible to perform radio wave misfire (for example, connection to a satellite other than the designated satellite, frequency / modulation method, It is possible to prevent the occurrence of interference to other satellite line operators due to setting errors of bandwidth, transmission power, and transmission polarization plane).
(5) Since the generation of the interference can be prevented, an environmental test (sway (vibration) / running movement) of the ESV system or the like can be performed.
(6) A confirmation test related to the antenna system apparatus can be performed, and a system test can be easily realized.
(7) In addition to confirming the operation of a new ESV system, it can be used for system development, system change, and equipment maintenance work.

In addition, since the parent device constituting the satellite simulation system of the present invention has a delay generation device, various functions and performance tests can be performed in consideration of the distance from the actual communication satellite.
(Effect in 2nd invention)
According to the second invention, since the frequency converter of the pseudo satellite communication device has a frequency level adjustment function, even if the master unit and the slave unit receive a downlink signal from an actual geostationary satellite, The influence on the satellite simulation system in the invention can be suppressed.

(Effects of the third invention)
By installing an antenna control device in the slave unit, it is possible to check the operation of switching satellites using multiple pseudo satellite communication devices and slave units, which greatly increases the cost compared to testing on an actual ship. In addition to the reduction, it is not necessary to use a large number of mixers and distributors when connecting to a plurality of slave units, and wiring is not complicated.
(Effects of the fourth invention)
By providing a delay generator in the master unit, various functions and performance tests can be performed in consideration of the distance from the actual communication satellite.

It is a figure showing an example of the satellite communication simulation system which concerns on one Embodiment of this invention. It is a conceptual diagram showing the ESV system using a communication satellite.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
(Satellite communication simulation system 100)
The satellite communication simulation system 100 according to the present invention performs a communication function test and a system performance test of the ESV system 200 that is bidirectionally communicated between the HUB station 70 and the ESV station 80 via a communication satellite as a communication satellite. By using the pseudo-satellite communication device 10 which is a station, it is provided at a bench test level in an indoor space such as a factory.
The satellite communication simulation system 100 simulates a space station 60, which is a communication satellite used when operating the ESV system 200, as shown in FIG. 2, and a HUB station 70 and an ESV station 80 installed on the ground. As shown in FIG. 1, the pseudo satellite communication device 10, the parent device 20, and the child device 30 are configured.

The parent device 20 and the child device 30 can communicate bidirectionally via the pseudo satellite communication device 10.
The communication function test and the system performance test are executed by simulation programs of simulation software installed in the first external terminal 50 and the second external terminal 51 respectively connected to the master unit 20 and the slave unit 30. Each test result can be confirmed by whether or not the master unit 20 and the slave unit 30 have received the control signal of the simulation program sent from the first external terminal 50 and the second external terminal 51.
(Pseudo Satellite Communication Device 10)
The pseudo-satellite communication device 10 is a weak radio station in which the emission intensity of radio waves is set to be equal to or less than that of the weak radio stations defined in the Radio Law.

Here, the emission intensity of the radio wave defined in the Radio Law is as shown below.
(1) At a distance of 3 m from the pseudo satellite communication device 10, the frequency band of the radio wave exceeds 322 MHz and is 10 GHz or less, and the electric field strength is 35 μV / m or less.
Or
(2) The radio frequency band exceeds 10 GHz and is 150 GHz or less and the electric field strength is 3.5 fμV / m or less at a distance of 3 m from the pseudo satellite communication device 10.
Further, as shown in FIG. 1, the pseudo satellite communication device 10 includes a horn antenna 11 that is an antenna, a transmitter / receiver demultiplexer 12 connected to the horn antenna 11, and a matching connected to the transmitter / receiver demultiplexer 12. And a frequency converter 14 connected to the matching unit 13.

The horn antenna 11 receives an uplink signal 40 transmitted from the parent device 20 and the child device 30, and transmits a downlink signal 41 to be transmitted to the parent device 20 and the child device 30.
The duplexer 12 separates the uplink signal 40 received by the horn antenna 11 and the downlink signal 41 transmitted from the horn antenna 11 with a separation degree of 40 dB or more.
The frequency converter 14 converts the frequency of the uplink signal 40 separated by the transmitter / receiver demultiplexer 12 and sent via the matching unit 13 into a frequency suitable for the downlink signal 41.

That is, the uplink signal 40 received by the horn antenna 11 is sent to the frequency converter 14 via the transmitter / receiver demultiplexer 12 and the matching unit 13 and converted to the downlink signal 41. The converted downlink signal 41 is transmitted from the horn antenna 11 to the master unit 20 or the slave unit 30 via the transmission / reception duplexer 12 and the matching unit 13.
Further, in order to prevent the base unit 20 and the slave unit 30 from receiving a downlink signal 41 from an actual geostationary satellite, the functional test of the bidirectional communication between the master unit 20 and the slave unit 30 is not affected. The pseudo-satellite communication device 10 is preferably provided with a frequency level adjustment function.

(Base 20)
The base unit 20 is connected to the first external terminal 50 in which simulation software is installed, and the simulation program control signal sent from the first external terminal 50 is sent to the handset 30 via the pseudo satellite communication device 10. This is a device that transmits and receives a control signal transmitted from the second external terminal 51 connected to the slave unit 30 via the pseudo satellite communication device 10.
Base unit 20 uses base unit antenna 21 that transmits and receives signals to and from horn antenna 11, base unit control device 22 that controls signals to be transmitted and received, spectrum analyzer 25 that measures frequency characteristics of radio waves, and actual communication satellites. A delay generator 26 that simulates a transmission time delay that sometimes occurs, a master network communication device 23 such as a router for establishing a communication network with the first external terminal 50, a master server 24, and other necessary devices It has. Here, base unit antenna 21 receives downlink signal 41 transmitted from pseudo satellite communication apparatus 10 and transmits uplink signal 41 to pseudo satellite communication apparatus 10.

(Master unit control device 22)
The base unit control device 22 controls the downlink signal 41 sent from the pseudo satellite communication device 10 and the uplink signal 40 sent to the pseudo satellite communication device 10.
The base unit control device 22 includes a base unit transmission / reception duplexer 22a, a base unit receiver 22b, an IF distributor 22c, a base unit modulation / demodulation device 22d, an IF combiner 22e, and a base unit frequency converter 22f.
The base transceiver duplexer 22a separates the uplink signal 40 and the downlink signal 41.

The master receiver 22b receives the downlink signal 41 separated by the master transmitter / receiver demultiplexer 22a and sends it to the IF distributor 22c.
The IF distributor 22c sends the downlink signal 41 sent from the master receiver 22b to the spectrum analyzer 25 and the master modulator / demodulator 22d.
A delay generator 26 is connected to the master modulation / demodulation device 22d, and the master modulation / demodulation device 22d modulates a control signal sent from the first external terminal via the delay generation device 26.
The IF synthesizer 22e synthesizes the signal sent from the delay generator 26 and modulated by the base modem modulator / demodulator 22d.

The base unit frequency converter 22f converts the signal combined by the IF combiner 22e into a frequency suitable for the uplink signal 40.
(Delay generator 26)
The delay generator 26 reflects a transmission time delay that occurs when an actual communication satellite is used when sending a control signal sent from the first external terminal to the parent device controller 22.
When the HUB station 70 and the ESV station 80 communicate with an artificial satellite or the like on a geostationary satellite orbit, the radio wave propagation is delayed depending on the propagation distance. Here, a delay occurring during radio wave propagation is defined as a delay time.

  Specifically, when the communication satellite is “Euelsat-172A” in a geostationary orbit at 172 ° east longitude, the propagation distance is 41,346 km at the maximum and 35,787 km at the minimum, and a delay time of 119 sec to 138 sec occurs. (See Table 1). Here, the maximum value and the minimum value of the propagation distance are determined by the elevation angle at which the communication satellite is viewed from the HUB station 70 or the ESV station 80 which is the earth station. The minimum value of the propagation distance is below the equator immediately below the communication satellite and the elevation angle is 90 °, and the maximum value is when the earth station is installed at a position where the elevation angle is 3 °. When the propagation distance becomes maximum, the delay time becomes maximum (maximum delay time), and when the propagation distance becomes minimum, the delay time becomes minimum (minimum delay time).

Since this delay time is determined by the propagation distance of radio waves, the delay time can be obtained by setting the target communication satellite. That is, the delay time is a fixed value that can be set during simulation.
Therefore, when transmitting the control signal of the simulation program to the master control device 22, the simulation result reflecting the delay time generated when the actual communication satellite line is used by transmitting via the delay generator 26. Will be obtained.
(Slave unit 30)
The ESV machine 30 is connected to the second external terminal 51, receives the control signal sent from the first external terminal 50 connected to the parent machine 20 via the pseudo satellite communication device 10, and receives the second external terminal This is a device that transmits a simulation program control signal sent from the terminal 51 to the parent device 20 via the pseudo satellite communication device 10.

  The handset 30 includes a handset antenna 31 that transmits and receives signals to and from the horn antenna 11, a handset control device 32 that controls signals to be transmitted and received, and a handset network such as a router for constructing a communication network with the second external terminal 51. A communication device 33, a slave server 34, an aerial control device 35 equipped with a GPS simulator or the like for confirming the operation of the automatic satellite switching function with a plurality of satellite simulators, and other necessary equipment Yes. Here, the slave antenna 31 receives the downlink signal 41 transmitted from the pseudo satellite communication device 10 and transmits the uplink signal 40 to the pseudo satellite communication device 10.

(Slave unit control device 32)
The slave control device 32 controls the downlink signal 41 sent from the pseudo satellite communication device 10 and the uplink signal 40 sent to the pseudo satellite communication device 10.
The slave unit control device 32 includes a slave unit transmitting / receiving duplexer 32a, a slave unit receiver 32b, a slave unit modulator / demodulator 32c, and a slave unit frequency converter 32d.
The handset transmission / reception duplexer 32a separates the uplink signal 40 and the downlink signal 41.

The slave receiver 32b receives the downlink signal 41 separated by the slave transmitter / receiver demultiplexer 32a and sends it to the slave modulator / demodulator 32c.
The slave unit modem device 32c is connected to the slave unit network communication device 33, the slave unit server 34, and the antenna control unit 35. The slave unit modem unit 32c demodulates the downlink signal 41 received by the slave unit receiver 32b. The control signal transmitted from the second external terminal 51 via each device is modulated while being transmitted to the second external terminal 51 via each device.
The handset frequency converter 32d converts the control signal demodulated by the handset modulator / demodulator 32c into a frequency suitable for the uplink signal 40.

(ESV system 200)
The satellite communication simulation system 100 is for testing various functions and performances of bidirectional communication between the HUB station 70 and the ESV station 80 in an environment equivalent to the ESV system 200 using an actual satellite communication line. . Therefore, the ESV system 200 will be described.
The ESV system 200 performs two-way communication between the HUB station 70 and the ESV station 80 via the space station 60 which is a communication satellite on a geostationary satellite orbit.
The frequency bands of radio waves used for two-way communication of the ESV system 200 are C band (uplink frequency band is 6 GHz band, downlink frequency band is 4 GHz band), Ku band (uplink frequency band is 14 GHz band, downlink) The frequency band is 12 GHz band, or Ka band (uplink frequency band is 30 GHz band, downlink frequency band is 20 GHz band), but can also be applied to L band, S band, and X band.

Communication methods include time division multiple access (TDMA), frequency division multiple access (FDMA), code division multiple access (CDMA), etc. Is done.
As shown in FIG. 2, the ESV system 200 includes a space station 60 that is a communication satellite, and a HUB station 70 and an ESV station 80 that are installed on the ground and communicate with each other via the space station 60.
The space station 60 includes a space station antenna 61, a space station duplexer 62, a space station amplifier 63, and a space station frequency converter 64.

The HUB station 70 includes a HUB station antenna 71 and a HUB station control device 72. The HUB station controller 72 includes a HUB station transmitter / receiver demultiplexer 72a, a HUB station amplifier 72b, a HUB station frequency converter 72c, and a HUB station modem 72d.
The ESV station 80 includes an ESV station antenna 81 and an ESV station control device 82. The ESV station controller 82 includes an ESV station duplexer 82a, an ESV station amplifier 82b, an ESV station frequency converter 82c, and an ESV station modem 82d.
In the ESV system 200, a case in which it is confirmed that the control signal transmitted from the HUB station 70 has been received by the ESV station apparatus 80 is shown below.

An external terminal (not shown) that sends a control signal is connected to the HUB station modem 72d. The control signal sent from the external terminal is modulated by the HUB station modulator 72d, and an uplink signal is sent by the HUB station frequency converter 72c. Converted to a frequency suitable for 40. The uplink signal 40 is amplified by the HUB station amplifier 72b and emitted from the HUB station antenna 71 to the space station 60 via the HUB station transmitter / receiver demultiplexer 72a.
In the space station 60, the uplink signal 40 is received by the space station antenna 61. The received uplink signal 40 is sent to the space station amplifier 63 via the space station demultiplexer 62, amplified by the space station amplifier 63, and converted to a frequency suitable for the downlink signal 41 by the space station frequency converter 64. Is done. The downlink signal 41 is amplified by the space station amplifier 63 and emitted from the space station antenna 61 to the ESV station 80 via the space station duplexer 62.

In the ESV station 80, the downlink signal 41 from the space station 60 is received by the ESV station antenna 81. The received downlink signal 41 is sent to the ESV station amplifier 82b via the ESV station transceiver 82a and amplified by the ESV station amplifier 82b. Next, the ESV station frequency converter 82c converts the frequency so that the transmitted downlink signal 41 can be received by an external terminal (not shown) connected to the ESV station, and is received by the ESV station modem 82d. Demodulated to a signal.
The demodulated received signal is transmitted to an external terminal (not shown) connected to the ESV station modem 82d, so that the ESV station 70 has received the control signal transmitted from the HUB station 70 side. Can be confirmed.

Next, a case where it is confirmed in the ESV system 200 that the control signal transmitted from the ESV station 80 has been received by the HUB station 70 is shown below.
An external terminal (not shown) for sending a control signal is connected to the ESV station modem 82d. The control signal sent from the external terminal is modulated by the ESV station modulator 82d, and an uplink signal is sent by the ESV station frequency converter 82c. Converted to a frequency suitable for 40. The uplink signal 40 is amplified by the ESV station amplifier 82b and emitted from the ESV station antenna 81 to the space station 60 via the ESV station transceiver 82a.

In the space station 60, the uplink signal 40 is received by the space station antenna 61. The received uplink signal 40 is sent to the space station amplifier 63 via the space station demultiplexer 62, amplified by the space station amplifier 63, and converted to a frequency suitable for the downlink signal 41 by the space station frequency converter 64. Is done. The downlink signal 41 is amplified by the space station amplifier 63 and emitted from the space station antenna 61 to the HUB station 70 via the space station duplexer 62.
In the HUB station 70, the downlink signal 41 from the space station 60 is received by the HUB station antenna 71. The received downlink signal 41 is sent to the HUB station amplifier 72b via the HUB station duplexer 72a and amplified by the HUB station amplifier 72b. Next, the HUB station frequency converter 72c converts the frequency so that the transmitted downlink signal 41 can be received by an external terminal (not shown) connected to the HUB station 70, and is received by the HUB station modem device 72d. Demodulated to a signal.

The demodulated reception signal is transmitted to an external terminal (not shown) connected to the HUB station modulation / demodulation device 72d, thereby confirming that the HUB station 70 has received the control signal transmitted from the ESV station 80 side. Can be confirmed.
(Execution of satellite communication simulation system 100)
Next, a case where the performance test of the ESV system 200 described above is performed using the satellite communication simulation system 100 described above will be described.
As described above, the system performance test is executed by the simulation program of the simulation software installed in the first external terminal 50 and the second external terminal 51 connected to the parent device 20 and the child device 30, respectively. Each test result can be confirmed by whether or not the master unit 20 and the slave unit 30 have received the control signal of the simulation program sent from the first external terminal 50 and the second external terminal 51. Therefore, a method for confirming whether or not the program control signal has been received will be described.

  Here, the ESV system 200 uses lines in the Ku band, the C band, the Ka band, and other frequency bands. However, in the satellite communication simulation system, the actual satellite communication line is used by setting the pseudo satellite communication apparatus 10 which is a weak radio station to the lines shown in Tables 2 to 4 instead of the lines in these frequency bands. The ESV system 200 is simulated by the satellite communication simulation system 100 in an environment equivalent to time. Here, Table 2 shows an example of the Ku band, which is a maximum level diagram and an operation level diagram for making the pseudo satellite communication apparatus 10 a weak radio station. Table 3 is an example of a C band, which is a maximum level diagram and an operation level diagram for making a weak radio station. Table 4 shows an example of a Ka band, which is a maximum level diagram and an operation level diagram for making a weak radio station.

First, a case where the satellite communication simulation system 100 confirms that the slave unit 30 has received the simulation program control signal transmitted from the first external terminal 50 connected to the master unit 20 will be described below.
Since the first external terminal 50 constructs a communication network with the parent device 20, the control signal of the simulation program transmitted from the first external terminal 50 is transmitted through the parent device network communication device 23 and the delay generation device 26. It is sent to the modem 22d and modulated. By being sent via the delay generator 26, the control signal can be sent in consideration of the delay time of the round-trip satellite section generated between the parent device 20 and the child device 30. Next, the control signal modulated by the base unit modulation / demodulation device 22d is converted into a weak radio wave frequency suitable for the uplink signal 40 by the base unit frequency converter 22f via the IF combiner 22e. The uplink signal 40 is emitted from the parent device antenna 21 to the pseudo satellite communication device 10 via the parent device transmission / reception duplexer 22a.

In the pseudo-satellite communication apparatus 10, the uplink signal 40 is received by the horn antenna 11. The received uplink signal 40 is sent to the matching unit 13 via the transmission / reception duplexer 12, impedance matched, and converted to a frequency suitable for the downlink signal 41 by the frequency converter 14. The downlink signal 41 is impedance-matched by the matching unit 13 and emitted from the horn antenna 11 to the slave unit 30 via the transmission / reception duplexer 12.
In the slave unit 30, the downlink signal 41 from the pseudo satellite communication device 10 is received by the slave unit antenna 31. The received downlink signal 41 is received by the slave receiver 32b via the slave transmitter / receiver demultiplexer 32a, and demodulated into a received signal by the slave modulator / demodulator 32c. The demodulated received signal is transmitted to the second external terminal 51 connected to the slave unit 30 via the slave unit network communication device 33 via the communication network. By transmitting the reception signal to the second external terminal 51 connected to the child device 30, it can be confirmed that the child device 30 has received the control signal transmitted from the parent device 20 side.

Next, a case where the satellite communication simulation system 100 confirms that the master unit 20 has received the control signal of the simulation program transmitted from the second external terminal 51 connected to the slave unit 30 is shown below.
Since the second external terminal 51 establishes a communication network with the handset 30, the simulation program control signal transmitted from the second external terminal 51 is sent to the handset modem 32c via the handset network communication device 33. And modulated. Next, the frequency is converted into a weak radio wave frequency suitable for the uplink signal 40 by the slave frequency converter 32d. The uplink signal 40 is emitted from the slave unit antenna 31 to the pseudo satellite communication device 10 via the slave unit transmission / reception duplexer 32a.

In the pseudo-satellite communication apparatus 10, the uplink signal 40 is received by the horn antenna 11. The received uplink signal 40 is sent to the matching unit 13 via the transmission / reception duplexer 12, impedance matched, and converted to a frequency suitable for the downlink signal 41 by the frequency converter 14. The downlink signal 41 is impedance-matched by the matching unit 13 and emitted from the horn antenna 11 to the base unit 20 via the transmission / reception duplexer 12.
In base unit 20, downlink signal 41 from pseudo satellite communication apparatus 10 is received by base unit antenna 21. The received downlink signal 41 is received by the master receiver 22d via the master transmitter / receiver demultiplexer 22a, demodulated into a received signal by the master modulator / demodulator 22d via the IF distributor 22c. Here, the downlink signal 41 is also sent to the spectrum analyzer 25 in order to measure the frequency characteristics of the radio wave by the IF distributor 22c.

The demodulated reception signal is transmitted to the first external terminal 50 connected to the parent device 20 via the communication network via the parent device network communication device 23. By transmitting the reception signal to the external terminal connected to the parent device 20, it can be confirmed that the parent device 20 has received the control signal transmitted from the child device 30 side.
(Summary)
By using the satellite communication simulation system 100 configured as described above, the following performance test can be performed as a system performance test and a communication function test of the ESV system 200.
1. Check the automatic satellite acquisition and tracking functions.

2. Check the function to select the signal receiving port by software.
3. Radio wave emission stop function (1) To confirm the radio wave emission stop function controlled by the reception state of the carrier such as a reception TDM (Time Division Multiplex).
(2) Confirm the radio wave emission stop function at the time of failure of the HUB station 70 or the ESV station 80.
(3) Confirm the radio wave emission stop function under the control of the HUB station 70.

(4) Confirm the radio wave emission stop function in the sea area where the ESV system 200 cannot be operated and within 125 km from the low tide line of each coastal country. (The above is for the Ku band and C band, within 300 km from the low tide line)
4). Confirm the control function of the emitted radio wave intensity, the monitoring and control function of the EIRP (effective isotropic radiant power) of the ESV system 200.
5. Confirm the monitoring and control functions of the main equipment of the ESV system 200 and the remote maintenance functions.

6). Confirm the function to periodically report the route information of the ESV system 200 to the HUB station 70 and the necessary bases on the ground.
7). Confirm the function of automatically performing UAT (Uplink Access Test).
8). By adjusting the EIRP (effective isotropic radiant power) of the master unit 20, the pseudo satellite communication device 10, and the slave unit 30, the system can be operated at the system operation level diagram and at the threshold level that simulates rain attenuation, etc. Perform operational evaluation of.

9. Perform system tests with variable line parameters (transmission speed, modulation method, error correction rate, required bandwidth, etc.) of master unit 20, pseudo satellite communication device 10, and slave unit 30.
10. The operation of the automatic satellite switching function should be confirmed by the state of capturing the moving satellite by a GPS simulator or the like attached to the antenna control device of the slave unit 30 or by a plurality of satellite simulators.
These functions are executed in each terminal by a simulation program of simulation software installed in the first external terminal 50 and the second external terminal 51 connected to the parent device 20 and the child device 30. The various functions executed by each terminal by the program are whether or not the control signals of the various functions are transmitted / received between the master unit 20 and the slave unit 30 via the pseudo satellite communication device 10 described above. Can be confirmed.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such embodiments, and various modifications can be made within the technical scope grasped from the description of the claims. It is. Also, although the ESV system 200 has been described, it can also be used for VSAT systems and other satellite communication systems.

10 Pseudo-satellite communication device 11 Antenna (horn antenna) 12
13 Matching device 14 Frequency converter
20 Base unit 21 Base unit antenna (base unit antenna) 22 Base unit controller
22a Main unit transmitter / receiver demultiplexer 22b Main unit receiver 22c IF distributor
22d Base unit modulator / demodulator 22e IF combiner 22f Base unit frequency converter
23 Base unit network communication device 24 Base unit server
25 Spectrum analyzer 26 Delay generator
30 Slave unit 31 Slave unit antenna 32 Slave unit control device
32a Slave unit transmitter / receiver duplexer 32b Slave unit receiver 32c Slave unit modem
32d Slave station frequency converter 33 Slave unit network communication device 34 Slave unit server
35 Slave antenna control system
40 Uplink signal 41 Downlink signal
50 First external terminal 51 Second external terminal
60 Space Station 61 Space Station Antenna 62 Space Station Demultiplexer
63 Space Station Amplifier 64 Space Station Frequency Converter
70 HUB station 71 HUB station antenna 72 HUB station controller
72a HUB station duplexer 72b HUB station amplifier
72c HUB station frequency converter 72d HUB station modem
80 Slave station (ESV station) 81 Slave station antenna 82 Slave station controller
82a ESV station transmitter / receiver 82b ESV station amplifier
82c ESV station frequency converter 82d ESV station modem
100 Satellite communication simulation system 200 ESV system

Claims (4)

A satellite communication simulation system for simulating a communication function of a bidirectional communication system between a HUB station and a slave station via a communication satellite,
The satellite communication simulation system includes:
A pseudo-satellite communication device that is a weak radio station set within a range stipulated in the Radio Law, and a parent device and a slave device that perform two-way communication via the pseudo-satellite communication device,
The pseudo satellite communication device includes:
An antenna for transmitting and receiving radio waves between the HUB station and the slave station;
A frequency converter that receives radio waves emitted from the HUB station or the slave station and converts the frequency of the received radio waves to a predetermined frequency, and
The base unit is
A master antenna that transmits and receives radio waves to and from the antenna;
A master control device for controlling transmission / reception of radio waves between the master antenna and the antenna;
A satellite communication simulation system comprising: a delay generation device that reflects a delay time generated in an actual satellite communication line in a simulation.   2. The satellite communication simulation system according to claim 1, wherein the frequency converter has a frequency level adjusting function for receiving a downlink signal emitted from the communication satellite by the master unit and the slave unit.   The satellite communication simulation system according to claim 1, wherein the slave unit includes an antenna control device that is a GPS simulator that simulates a moving state of the slave unit. A base unit that transmits and receives radio waves to and from a pseudo-satellite communication device that is a weak radio station whose radio wave emission intensity is set within the range specified by the Radio Law,
Two-way communication with the slave via the pseudo satellite communication device,
A master antenna that transmits and receives radio waves to and from the pseudo satellite communication device;
A master control device that controls transmission and reception of radio waves between the master antenna and the pseudo satellite communication device;
A master unit comprising: a delay generation device that reflects a delay time generated in an actual satellite communication line in two-way communication with a slave unit.