JPS62279725A - Satellite relay mobile body communication system - Google Patents

Abstract

PURPOSE:To obtain an economical satellite relay mobile body communication system by using separate frequencies for the transmission/reception of a 3rd transmission/reception equipment being a mobile station and a 2nd transmission/ reception equipment being a base station opposed to a 3rd transmission/reception equipment. CONSTITUTION:A talker applies press-to-talk operation to a transceiver 4, then the transceiver 4 sends a transmission wave of a frequency f21 to interrupt the reception output. A transmission/reception equipment 15 of an opposed slave station 3 receives and demodulates the wave, outputs an IF signal modulated by a sound output signal by a channel unit 13 and an up-link wave is sent from a transmission/reception equipment 12. The uplink wave is received by a central station 2 and all slave stations 3 via a satellite communication line 101. The sound output signal demodulated by the slave station 3 is sent from the transmission/reception equipment 15 as a transmission wave of the frequency f11 and received by an opposed transceiver 4. The communication by a transceiver 5 is executed similarly. Thus, the corresondence of one to one or of the conference system is executed by the press-to-talk system.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a satellite relay mobile communication system, and particularly to a satellite relay mobile communication system that uses both a satellite communication line and a terrestrial wireless communication line. Regarding communication systems.

[Conventional technology]

A mobile communication system in which the transmitting frequency and the receiving frequency are the same frequency in the VHF band or UHF band, and a large number of callers communicate with each other using a silent talk transceiver,
With the exception of breathtalk operations, the transmission waves of any transceiver can be received simultaneously by all other transceivers without complex and expensive controls such as transmitting/receiving frequency control, allowing not only one-on-one communication but also conference-type communication. It can also be done economically. In order to expand the communication range of such a mobile communication system to ultra-high-speed distances, such as between the headquarters area and the vicinity of a branch office of a single corporate entity, a 5CPC half-duplex satellite communication line is used to relay between transceivers. A satellite relay mobile communication system is being considered.

In the conventional satellite relay mobile communication system,
A base station transceiver for connecting a transceiver to an earth station via a terrestrial wireless communication line must transmit and receive at the same frequency, just like the transceiver. When the transceiver sends out a transmission wave, the base station receives it and outputs a reception output signal, and this output becomes the transmission human signal of the earth station, and the earth station sends out the transmission wave to the outer space. This transmitted wave is relayed in the space center and received by the opposing earth station, and is also received by the earth station that transmitted it, so this earth station outputs a reception output signal, and this output is transmitted to the base station. This becomes the transmission input signal. When a base station transceiver is in constant operation, this base station transmits a transmission wave, and the receiver of this base station is masked by this transmission wave and becomes unable to receive it. In order to avoid such a situation, it is necessary to turn on and off the transmitter of the base station in response to the breathtalk operation of the opposing transceiver.

[Problem to be Solved by the Invention 3] As explained above, in the conventional satellite relay mobile communication system, the base station transceiver uses the same frequency for transmitting and receiving, and the transceiver facing the transmitter does not support the breathtalk operation. Since it is necessary to perform on/off control using a manual control device, a complicated and expensive automatic control device or manual control operations by personnel resident at the base station are required, and there is also a drawback that reliability is reduced.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks and provide an economical satellite relay mobile communication system that does not require controlling the operation of base station transceivers.

Means for Solving Problem c] The satellite relay mobile communication system of the present invention is for a satellite communication line, and includes a voice-driven first transceiver, and a terrestrial wireless communication line, for transmitting and receiving. Using the side frequency,
a second transceiver whose reception output signals and transmission input signals are the transmission input signal and reception output signal of the first transceiver; and a third transceiver that is movable and wirelessly connected to the second transceiver. It is configured with a transmitter/receiver.

〔Example〕

The present invention will be described in detail below with reference to drawings showing embodiments.

FIG. 1 is a block diagram showing an embodiment of the satellite relay mobile communication system of the present invention.

In the embodiment shown in FIG.
a space department 1 that relays satellite communication lines 101 and 102 of the 5CPC system, which are It is equipped with a plurality of breathtalk type transceivers 4 and 5 connected to each of the slave stations 3 via terrestrial wireless communication lines 201 and 202 that use frequencies 711/21 and 8z-/zz for transmission and reception, respectively. It is composed of

The central station 2 includes an antenna 11 and a channel unit 13.
・Only when an intermediate frequency (hereinafter referred to as IF) signal from 14 is input, an uplink wave of frequency /ux/fuz is sent out via the antenna 11, and a downlink wave /ax-/ax is sent out via the antenna 11. a transceiver 12 that receives the IP address and outputs the IP multiplied signal to the channel units 13 and 14;
Only when an audio input signal is input from a breath-talk type transmitter/receiver (not shown) connected to each, an IF multiplied signal modulated by this audio input signal is output to each transmitter/receiver 12. The transceiver 12 is driven by voice (
voice activation) L, transceiver 1
Channel unit 1 demodulates each IF multiplied signal input from 2 and outputs an audio output signal to each handset.
3.14.

The slave station 3 has an antenna 1 which operates in the same way as at the central station.
1. Transmitter/receiver 12 and channel unit 13.]
4, antennas 17 and 18, and channel unit 13
・Frequency/1 each modulated by 14 audio output signals
Transmission waves of t·/lz are sent out through antennas 17 and 18, respectively, and frequency ! is transmitted through antennas 17 and ]8. 21
- Transmitter/receivers 15 and 16 respectively receive and demodulate the 722 received waves and output audio output signals to channel units ]3 and 14, respectively.

When one of the callers operates the transceiver 4 to make a call, the transceiver 4 transmits a transmission wave with a frequency of 721 and cuts off the reception output.

This transmitted wave is modulated by the voice input of the caller. The transceiver 15 of the opposing slave station 3 receives and demodulates the transmitted wave from the transceiver 4 via the terrestrial wireless communication line 201 and the antenna 17, and outputs an audio output signal. While this audio output signal is being output, the channel unit 13 outputs an IP multiplied signal modulated by this audio output signal, and this IF multiplied signal is audio driven and the transceiver 12 transmits the frequency / u s via the antenna 11. sends out uplink waves. This uplink wave is received by the antenna 11 and transceiver 12 of the central station 2 and all slave stations 3 via the satellite communication line 101. becomes the output signal. This audio output signal drives a transceiver connected to channel unit 13 in central station 2, and is sent out as a transmission wave at frequency 711 in slave station 3 via transceiver 15 and antenna 17. This transmitted wave is received by the opposing transceiver 4. However, since the reception output of the transceiver 4 to which the audio is input is turned off, the transceiver 4 does not output a return audio of the audio input at its own station via the interspace 1. The transmission from the handset connected to the central station 2 is carried out in the same manner as described above, except that it does not go through the terrestrial radio communication line.

As explained above, all callers using transceivers 4 and callers using handsets connected to channel unit 13 of central station 2 communicate via satellite communication line 101 and terrestrial wireless communication line 201. One-on-one communication or conference-type communication can be performed in a breath-talk manner. All callers using transceivers 5 as well as callers using handsets connected to channel unit 14 of central office 2 are connected to satellite communication line 102.
Similarly, they can communicate with each other via the terrestrial wireless communication line 202.

The transceivers 15 and 16 use different frequencies for transmission and reception, and can receive the transmission waves even while they are being transmitted, so they may operate all the time, and there is no need to perform on/off control.

Note that the transceivers 4 and 5 and the transceiver connected to the central station 2 do not need to cut off the reception output even during voice input, if the inconvenience of listening to the return voice via interspace 1 is acceptable. Therefore, breathtalk operation of these transceivers and handsets is not necessarily required.

Similarly to the slave station 3, the central station 2 is also equipped with transmitters/receivers 15 and 16 and antennas 17 and 8,
It is also possible to connect the central office 2 to transceivers 4, 5 via 01, 202.

Normally, commercially available transceivers are configured to use two crystal oscillators to independently set the transmitting frequency and receiving frequency. ) and second transceivers (transceivers 15 and 16 in FIG. 1) without any particular modifications.

In the embodiment shown in FIG. 1, the central station 2 is located in the head office building of a business entity or the central office building of a government agency, the slave station 3 is located in a branch office building or a building of a branch office of a government agency, and the transceivers 4 and 5 are located in a branch office or branch office building. They are installed and used on moving objects scattered around the area.

Further, the slave station 3 itself can be made portable so that it can be installed anywhere.

〔Effect of the invention〕

As explained in detail above, the satellite relay mobile communication system of the present invention uses an existing satellite communication line such as the 5CPC system without adding any special control, and the third transceiver which is a mobile station and By setting the transmission and reception of the second transceiver, which is a base station facing the third transceiver, to different frequencies, there is no need to control on/off of the second transceiver, and the second and third transceivers Since a commercially available transceiver can be used without any special modifications, it is extremely economical.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the satellite relay mobile communication system of the present invention. 1... Interuniverse, 2... Central station, 3...
...Slave station, 4.5...Transceiver, 11
・17・18・・・・・・Antenna, 12・15・16
...Transmitter/receiver, 13/14...Channel unit. Agent Patent Attorney Susumu Uchihara, 2P・-1・′′P1 Figure

Claims (1)

[Claims] A first transmitter/receiver for a satellite communication line and driven by sound; and a transmitting input of the first transceiver for a terrestrial wireless communication line, using different frequencies for transmission and reception; A second transceiver that uses signals and reception output signals as reception output signals and transmission input signals, and a third transceiver that is movable and wirelessly connected to the second transceiver. Satellite relay mobile communication system.