JPH01240021A - Transmission system switching equipment for multi-direction multiplex communication equipment - Google Patents

Abstract

PURPOSE:To reduce cost and passing loss by providing a high frequency switch to switch-output the output of the transmitter of a living system and the output of the transmitter of a spare system by a system switching signal selectively and a means to stop-control the transmitting action of the transmitter of the system of a non- operating side based on the system switching signal and executing a transmitting system switching. CONSTITUTION:When a system switching signal to instruct the selection of a living system, for instance, is outputted from a switch-control circuit 3, a high frequency switch 4 selects the output signal of a living system transmitter 1 as a transmission high frequency signal. Then, the living system transmitter 1 is controlled to send a transmission signal for the high frequency switch 4 by inputting the system switching signal to a power source switch 9. On the other hand, since the system switching signal inversed through an inverter 11 is inputted to the power source switch 10 in a spare system transmitter 2, a high frequency amplifier 8 is controlled to stop an transmitting action. Consequently, since the stage number of a diode is small and an isolation quantity can be reduced, the whole device can be inexpensive and low passing loss is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an improvement in a transmission system switching device for a multi-directional multiplex communication device.

2. Description of the Related Art] A transmission system switching system shown in FIG. 2 has been conventionally adopted in a multi-directional multiplex communication device, particularly in a hot standby system that is duplexed by a working system and a protection system.

In the figure, 1 is a working transmitter, 2 is a backup transmitter,
3 is a switching control circuit, and 4 is a high frequency switch.

In the conventional system, the high frequency switch 4 is controlled by the system switching signal output from the switching control circuit 3, and the transmission output signal from the working system transmitter 1 and the transmission output signal from the standby system transmitter 2 are controlled. It was switched and output as a transmission high frequency signal.

However, in such a conventional system, two of the high frequency switchers 4
The output signal of the working transmitter 1 and the output signal of the protection transmitter 2 are simultaneously input to two inputs 611. For this reason, the transmission output signal of the non-operating side leaks into the transmission high frequency signal output from the output terminal of the high frequency switching device 4, causing co-channel interference, and the line quality deteriorates in proportion to this star. was there.

In addition, in order to prevent such deterioration of the line ratio, if a high frequency switch 4 with a large amount of isolation for the non-operating side is used, the high frequency switch 4 itself becomes expensive and the passing loss increases. There was a problem with this.

In particular, if a diode switch capable of high-speed switching is used as the high-frequency switch 4, it is necessary to increase the number of stages of diodes and increase the amount of isolation.
There are problems in that the price of the entire device becomes even more expensive and the passing loss increases.

[Problems to be Solved] The present invention has been made in view of these conventional problems, and its purpose is to provide a transmitter switching device for a multi-directional multiplex communication device that is inexpensive and has small passing loss. be.

[Means for Solving Problems] In order to achieve item 1 above, the present invention provides a device for switching the transmission system of a multi-directional multiplex communication device multiplexed by a working system and a protection system. a high frequency switching device that selectively switches output between the output of the transmitter of the system and the output of the transmitter of the standby system; and means for controlling the transmission operation of the transmitter of the non-operating system to stop based on the system switching signal; , is configured to include.

[Example code] Next, preferred embodiments of the present invention will be described based on the drawings.

Incidentally, members corresponding to those of the conventional example shown in FIG. 2 are given the same reference numerals, and their explanations will be omitted.

FIG. 1 shows a preferred example of a transmission system switching device for a multi-directional multiplex communication device according to the present invention.
is a working system transmitter, 2 is a standby system transmitter, 3 is a switching control circuit, 4 is a high frequency switch, 5゜6 is a modulator, 7 and 8 are high frequency amplifiers, 9 and 10 are power switches, 11 is an inverter It is.

The power switch 9.10 has a corresponding high frequency amplifier 7.
．． It is used to control the transmission stop of the transmission signal output from 8.

Further, the switching control amount #t3 outputs a system switching signal,
This system switching signal controls the high frequency switching device 4, is guided to the power switch 9 for the active system transmitter 1, and is sent to the power switch 9 for the standby system transmitter 2 via the inverter 1. Guided by 10.

This embodiment consists of the following cases, and the operation thereof will be explained next.

First, when the switching control circuit 3 outputs a system switching signal instructing selection of the active system, the high frequency 1'JJ switch 4 selects the output signal of the active system transmitter 1 as the transmission high frequency signal.

At this time, the active system transmitter 1 is controlled to send the transmission signal to the high frequency switch 4 by inputting the system switching signal to its power switch 9 .

On the other hand, since the system switching signal inverted via the inverter 11 is input to the power switch 1o in the standby system transmitter 2,
The high frequency amplifier 8 is controlled to stop transmitting operation.

Conversely, when the switching control amount #I3 outputs a system switching signal instructing backup system selection, the high frequency switching 4 selects the output signal of the backup system transmitter 2 as the transmission high frequency signal. . At this time, the active system transmitter 1 receives the system switching signal by inputting the system switching signal to its power switch 9.
Controlled to stop the transmission operation. On the other hand, the standby transmitter 2 is controlled to send out a transmission signal by inputting to the power switch 10 a system switching signal that has not been inverted by the inverter 11 .

As described above, according to the present invention, the high frequency switch 4 is switched and controlled, and the non-operating side transmitter 1. By controlling the transmission operation of t or 2 to stop, the transmission signal of the non-operating side that leaks into the transmission high frequency signal of the high frequency transmitter 4 is
Attenuation can be achieved by adding the isolation amount of the high-frequency switch 4 to the ratio of sending and stopping the transmission signal of the transmitter on the non-operating side.

Therefore, according to the present invention, the high frequency switch 4 can be formed with a small number of diode stages and a small amount of isolation, so the entire device can be made inexpensive and have low passing loss.

Note that the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the gist of the present invention.

[Effects of the Invention] As explained above, the present invention has the advantage that it is possible to provide an inexpensive transmission system switching device with small passing loss, which performs transmission system switching of a multidirectional multiplex communication device. .

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram showing a preferred example of a transmission system switching device of a multidirectional multiplex communication device according to the present invention, and FIG. 2 is a block circuit diagram showing an example of a conventional transmission system switching device. 1: Working system transmitter 2; Standby system transmitter 3: Switching control circuit 4: High frequency switch 5.6: Modulator 7.8: High frequency amplifier/width switch 9.10: Power switch 11: Inverter

Claims (1)

[Claims] (1) In a device that switches the transmission system of a multidirectional multiplex communication device multiplexed by a working system and a protection system, the output of the working system transmitter and the output of the protection system transmitter are selected by a system switching signal. A transmission system switching device for a multi-directional multiplex communication device, comprising: a high-frequency switch for switching output automatically; and means for controlling the transmission operation of a transmitter on a non-operating system to stop based on the system switching signal. Device.