JPS5850061B2 - communication facilities - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to communication between a mobile body and a base, or between mobile bodies.

BACKGROUND ART Conventionally, communication between mobile bodies and bases or between mobile bodies in mountainous areas has been carried out either via a mountain relay station or directly depending on the state of the wireless communication line.

FIG. 1 is a block diagram showing an example of a conventional communication facility of this type. In the figure, 1 is a transmitting device tuned to frequency A, 2 is a transmitting device tuned to frequency B, and 3 is a transmitting device tuned to frequency A. 4 is a receiving device tuned to the frequency of B; 5 is an antenna switching device; 6 is an antenna; 7 is a transmitting U inspection device; 8 is an antenna sharing device; 9 is a mobile or base communication station; 10 indicates a mobile communication station, and 11 indicates a relay station.

Next, ask questions about the movement.

When a caller at a certain communication station, for example communication station 9, operates the transmitter 1, the transmission switching device 7 is connected to the transmitting device 1, and when the antenna switching device 5 is in the transmitter mode due to a breath talk call, the transmission switching device 1 is connected to the transmitting device 1. When receiving a call, it is connected to the receiving device 3.

Since the radio wave of frequency A is used, it is received by the receiving device 3 via the antenna 6 and antenna switching device 5 of the partner station 10, and a call is made.

When there is no response from the other party's station 10, when the caller 9 operates the transmitter 2, the transmission switching device 7 is connected to the transmitter 2, and when the antenna switching device 5 is transmitting by breath talk communication, the transmission is switched. to device 7, and to receiving device 3 when receiving a call.
connected to.

Since the radio wave of frequency B is used, it is received by the receiving device 4 via the antenna 6 of the relay station 11 and the antenna sharing device 8, and the receiving device 4 starts the transmitting device 1, and the radio wave of frequency A is transmitted from the top of the mountain. Emit radio waves.

This radio wave is received by the receiving device 3 via the antenna 6 of the partner station 10 and the antenna switching device 5, and a call is made.

Since conventional communication facilities are configured as described above, it is necessary for the caller to select and switch the transmitter by determining the call status based on the presence or absence of a response from the other party to the call and the quality of the call. It had the disadvantage that it was impossible to always be connected to the better line.

This invention was made in order to eliminate the above-mentioned drawbacks in conventional communication facilities, and automatically selects whether to use a route via a relay station or a direct route between each other, so that the line on the better side is always selected. The purpose is to provide communication facilities that can maintain the

FIG. 2 is a block diagram showing an embodiment of the present invention,
In the figure, the same reference numerals as those in FIG. 1 indicate the same or equivalent parts, 12 is a distribution device that distributes input radio waves to receiving devices 3 and 4, and 13 is a device that determines the S/N of the outputs of receiving devices 3 and 4. Connect the line to the better S/N side with S/N.
N comparison device, 14 is a speaker that converts the received output into an acoustic signal, 15 is a microphone, 16 is the S/N of the output of the receiving device 4
17 is connected to the receiving device 3 installed in the relay station 11; A signal detection device is shown which detects the signal generated by the signal and activates the transmitting device 2 during the presence of this signal.

Furthermore, in the present invention, if the frequency of A is a first frequency, the receiving device 3 that receives this first frequency is a first receiving device, and the frequency of B is a second frequency, and this second frequency is received, The receiving device 4 will be referred to as a second receiving device.

Next, questions will be asked regarding the operation of the circuit shown in FIG.

First, a caller at the communication station 9 starts up the transmitting device 1 and puts it into a transmitting state.

In the receiving state immediately before entering this transmitting state, the S/N of the own station is
The comparison device 13 compares the outputs of the receiving devices 3.4, but since there is no input to either of the receiving devices 3.4, it cannot be determined which output has a larger S/N.

In the transmission state after such a state, the signal generator 16
is set to repeat the liquid cylinder.

When the signal generating device 16 is connected, a control signal selected at a frequency outside the audio band, for example, below the audio band and not perceptible to the ear, is modulated by the transmitting device 1 and transmitted.

If the signal generator 16 is turned off, the above-mentioned control signal will not be sent out.

When the signal generator 16 repeats the liquid cylinder, the radio waves emitted from the transmitter 1 of the communication station 9 intermittently transmit the above control signal, so while this control signal is being transmitted, the relay station 1
The signal detection device 17 in 1 operates to activate the transmitting device 2, and radio waves of the second frequency are emitted from the antenna 6.

On the other hand, if the control signal from the signal generator 16 is disconnected, the signal detector 17 becomes inactive and no radio waves are emitted from the relay station 11.

In the communication station 10, the radio waves of the first frequency from the communication station 9 and the radio waves of the second frequency from the relay station 11 are received by the receiving devices 3 and 4, respectively, and the radio waves of the second frequency are received by the signal detection device. 17 is transmitted only when a control signal is detected), the S/N of the outputs of the receivers 3 and 4 is compared, and if the S/N of the output of the receiver 4 is larger, the signal generator 16 is transmitted. Start it up and prepare to superimpose the control signal on audio and transmit it.

Further, if the output of the receiving device 3 has a higher S/N, no control signal is sent out.

When the communication station 10 is in the transmitting state, the S/N comparator 1
3 is the signal generator 1 depending on the state immediately before entering the transmitting state.
6 and maintains this state until the next reception state arrives.

On the other hand, on the communication station 9 side, since the radio waves via the relay station 11 are compared with the radio waves directly from the communication station 10, the better side can be selected until the own station shifts to the transmitting state.

In this way, once communication is carried out overnight between the communication stations 9 and 10, the S/N ratio can be automatically selected and a good radio wave path can be selected.

Route selection is not very delicate, and most service areas are usually fixed to radio waves on one of the routes.

In the above embodiment, the communication stations 9 and 10 were equipped with two receivers tuned to frequencies A and 8, respectively, but only the frequency tuning part was switched, the other parts were common, and a constant S/ It is also possible to adopt a system in which the frequency is switched to another frequency when the frequency becomes N or less.

As described above, according to the present invention, the S/N ratio between two radio wave paths is automatically selected and the transmitting device on the better side of the radio wave path is selected, so that the communication range can be expanded.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing a conventional communication facility of this type;
The figure is a block diagram showing one embodiment of the present invention. In the figure, 1 is a transmitting device tuned to a first frequency, 2 is a transmitting device tuned to a second frequency, 3 is a receiving device tuned to the first frequency, 4 is a receiving device tuned to the second frequency, 9 is a mobile or base communication station, 11 is a mobile communication station, 11 is a relay station, 12 is a distribution device, and 13 is an S/N
16 is a signal generator, and 17 is a signal detector. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] 1. In a communication facility including a plurality of communication stations that communicate with each other via a relay station or not via a relay station depending on the state of the wireless communication circuit, each of the above communication stations is equipped with a transmitter that transmits at a first frequency. , a first receiving device that receives the first frequency, a second receiving device that receives the second frequency, an S/N of the output of the first receiving device, and the second receiving device. and an S/N comparing device that compares the S/N of the output of the second receiving device, and a control device in the transmission after the S/N comparing device determines that the S/N of the output of the second receiving device is larger. a signal generating device that continuously transmits the signal and repeats transmission and stopping of the control signal in the transmission after the S/N comparator cannot determine which output has a larger S/N; The relay station includes a receiving device that receives the first frequency, a signal detecting device that detects the control signal, and a transmitting device that relays and transmits at the second frequency during the existence period of the output of the signal detecting device. A communication facility characterized by: