JPH02253725A - Service channel signal transmission system - Google Patents

Abstract

PURPOSE:To improve S/N by sending a service channel signal from one auxiliary line and plural living lines by a distributor in a transmission side, synthesizing service channel signals received from the respective lines by a synthesizer and receiving the synthesized signal in a reception side. CONSTITUTION:The service channel signal is inputted from an input terminal 1 to a distributor 2 and branched into N+1-number of signals. The signals are inputted to respective modulators 4 and transmitted through a transmitter 5 and a circulator 6 by a transmission antenna 7. The signals received by a reception antenna 8 go to be the service channel signal again by a circulator 9, receiver 10 and demodulator 11 and synthesized by a synthesizer 13. Afterwards, the synthesized signal is outputted from an output terminal 14. In such a way, for the service channel signal to be transmitted in a state that the signal is respectively branched into the N+1-number of the signals, a signal component is the same phase and on the other hand, a thermal noise component is a random phase. Thus, a signal-to-thermal noise ratio is improved by 10logMdB.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a service channel signal transmission system in a heterodyne radio system.

(Prior Art) Conventionally, this type of service channel signal transmission system uses only the protection line and one of the N working lines, switches between the protection line side and the working line side at the receiving side, and transmits the service channel signal. It was the way it came out.

Figure 2 shows an example, and (a) shows the feeding side,
The figure (b) shows the receiving side. On the sending side, the baseband signal input terminal 3. Modulator 4. It is composed of a transmitter 5, a circulator 6, and a transmitting antenna 7, and has one protection line and N working lines. Also, on the receiving side, a receiving antenna 8. Circulator9. Receiver 10. demodulator ll,
It is composed of a baseband signal output terminal 12, and similarly includes one protection line and N working lines.

Furthermore, on the sending side, there is a service channel signal input terminal l.
and a distributor 2, and the service channel signal is transmitted to the distributor 2.
The data is sent to the protection line and one working line. Further, the receiving side has a switching device 13A and a service channel signal output end 14, and receives the service channel signal by switching between the protection line and one working line.

[Problem to be solved by the invention]

In the conventional service channel signal transmission method described above, the signal-to-noise ratio of the service channel signal is determined by the amount of thermal noise generated by equipment on the transmission route because it is transmitted through either the protection line or the working line. The problem is that the signal-to-noise ratio is poor. Further, on the receiving side, it is necessary to control the switching device 13A for selecting a service channel signal in accordance with the sending side, which causes a problem that the control becomes troublesome and complicated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a service channel signal transmission system that improves the signal-to-noise ratio and is easy to control.

[Means to solve the problem]

The service channel signal transmission method of the present invention includes a distributor that distributes one service channel signal to a plurality of channels on the sending side, transmits the service channel signal through one protection line and a plurality of working lines, and transmits the service channel signal on the receiving side. A combiner is provided to combine the distributed signals into one, and the service channel signals received from each line are combined and received.

[Effect]

In the above-described method, the signal components have the same phase, while the noise components have random phases, improving the signal-to-noise ratio. Further, a switching device is not required on the receiving side, and its control is not required.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention, with (a) showing the sending side and (b) showing the receiving side.

On the sending side, baseband signal input terminals 3. are provided for each of the protection line and the N working lines. Modulator 4. Transmitter 5. A service channel signal input terminal 1 which is common to the circulator 6 and a circulator 6; It has a transmitting antenna 7. A service channel signal is inputted from an input terminal 1 to a distributor 2, branched into N+1 signals, inputted to each modulator 4, and transmitted to a transmitter 5. It is transmitted by a transmitting antenna 7 through a circulator 6.

In addition, on the receiving side, a circulator 9. Receiver 10. a receiving antenna 83 which is common to the demodulator 11 and a combiner 13 .
It has a service channel signal output terminal 14. The signal received by receiving antenna 8 is transmitted to circulator 9 . receiver io.

It becomes a service channel signal again by the demodulator 11,
After being synthesized by the synthesizer 13, the signals are output from the output terminal 14.

Therefore, in the service channel signals transmitted in a state where they are each branched into N+1, the signal components are in the same phase, but the thermal noise components are in random phase, so the signal to thermal noise ratio is (101ogM). This will result in a dB improvement.

Further, in this system, since the signals branched by the combiner 13 are combined and received on the receiving side, there is no need to use a switch, and therefore no control is required, making it possible to easily receive signals.

(Effects of the Invention) As explained above, the present invention allows a distributor to send service channel signals through one protection line and a plurality of working lines on the sending side, and receives them from each M line using a combiner on the receiving side. Since the service channel signals are combined and received, the signal components are in the same phase, while the noise components are in random phase, making it possible to improve the signal-to-noise ratio.

Furthermore, since the receiving side only needs to combine a plurality of signals, there is no need for a switch, and there is also the effect that the control thereof can be made unnecessary.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a block diagram of an embodiment of the present invention.
FIG. 2 is a block diagram of a conventional system, with FIG. 2(a) showing the sending side and FIG. 2(b) showing the receiving side. DESCRIPTION OF SYMBOLS 1... Service channel signal input terminal, 2... Distributor, 3... Baseband signal input terminal, 4... Modulator, 5... Transmitter, 6... Circulator, 7...
... Transmitting antenna, 8... Receiving antenna, 9... Circulator, 10... Receiver, 11... Demodulator,
12...Baseband signal output terminal, 13...Synthesizer, 13A...Switching, 4...Service channel signal output terminal. (a) Figure (b) a Figure 2 (b)

Claims (1)

[Claims] 1. When transmitting a service channel signal in a heterodyne wireless system in which the signal sent from the sending side is transmitted to the sending side using one protection line and multiple working lines,
A transmitting side is provided with a distributor that distributes one service channel signal to a plurality of signals, the service channel signal is sent out through each of the lines, and a receiving side is provided with a combiner that combines the distributed signals into one. , a service channel signal transmission system characterized in that service channel signals received from the respective lines are combined and received.