JPH01194620A - Control line transmission system - Google Patents

Abstract

PURPOSE:To set a control line having the same lines as the number of multi- carriers by carrying out frequency modulation(FM) by every independent control line signal of the multi-carrier by means of the phase modulating circuit(MOD) at every multi-carrier, and demodulating the FM-processed signal at every phase demodulating circuit(DEM) corresponding to each MOD. CONSTITUTION:In respective circuits MOD 201 and 202, the FM is processed by each independent ASC signal at every multi-carrier, and the FM is carried out by each ASC signal in an intermediate frequency band on the side of transmitters 301 and 302. Thus, the FM by different ASC(analog service channel) signals at every multi-carrier is processed. Demodulation is carried out in corresponding circuits DEM 501 and 502, and the different ASC signals in the respective circuit DEM 501 and 502 can be obtained. Consequently, the multi-carrier is at four waves, the ASC can be set at lines corresponding to it.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a system for transmitting control line signals using multicarriers in a digital microwave repeater.

[Conventional technology]

In digital microwave repeaters, ASC (Analog S@rvice Channel) is used as a control line.
For the purpose of transmitting the ASC signal, it is common to apply frequency modulation (hereinafter referred to as FM) to the ASC signal in the local oscillation circuit of the transmitter.

FIG. 2 is a block diagram showing a conventional digital microwave repeater, which includes a transmission side line switching device 101, a phase modulation circuit for each multicarrier (hereinafter referred to as MOD) 2
01, 202, microwave transmitter 301°302,
Receivers 401, 402, MOD20 facing these
1, 202 and corresponding phase demodulation circuit (hereinafter referred to as DEM)
501, 502, and the receiving side line switching device 60
1 to the transmitters 301 and 302.
The input of the SC is provided and the opposing receiver 401
The DEMs 501 and 502 are provided with ASC outputs via the DEMs 501 and 502, and the transmitters 301 and 502 receive each ASC signal.
FM is applied in the local oscillation circuit of 302, while FM is applied in each of the corresponding DEMs 501 + 502.
The signal is demodulated and the same ASC signal is obtained from each circuit of D]J501 and 502.

[Problem to be solved by the invention]

However, in the configuration of FIG. 2, the DEM501.

Each of the 502 circuits demodulates the same FM signal, and the demodulated outputs become the same ASC signal, so one line of ASCL cannot be transmitted and a large amount of control line capacity is required. In some cases, it is not possible to meet this requirement, resulting in a drawback.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention is configured by the following means.

That is, in the method of transmitting control line signals using multi-carriers described above, the MOD for each multi-carrier allows F to be transmitted by an independent control line signal for each multi-carrier.
The signal subjected to F'M is demodulated for each OEM corresponding to each MOD, and each control line signal is obtained from this demodulation plK.

[Effect]

Therefore, each multi-carrier transmits an independent control line signal by FM, and the number of control lines equal to the number of multi-carriers can be set.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to FIG. 1 showing an embodiment.

This figure is a block diagram similar to that of FIG. 2, and the configuration is also the same, but the input of the ASC is provided for each circuit of MOD 201 and 202, and the output of the ASC is also connected to the corresponding D.
Provided for each circuit of EM501 and 502, MOD
In each of the circuits 201 and 202, FM is performed using each independent ASC signal for each multicarrier, and each ASC signal is applied in the intermediate frequency band on the transmitter 301 and 302 side.
FM is performed using signals.

For this reason, FM using a different ASC signal is applied to each multicarrier, and this
It is demodulated in each circuit of DEM50
A different ASC signal is obtained for each circuit of 1 and 502.

Therefore, in this example, there are four multicarriers, and four ASC lines can be set accordingly, making it possible to quadruple the capacity of the control line compared to FIG. 2.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, J9 FM is applied to each multicarrier using a control line signal, and this is demodulated individually. It is possible to set the control line freely, especially in the case of multilevel phase modulation or low modulation speed, etc.
This is effective when a control line cannot be set between the opposing MOD and OEM, and a remarkable effect can be obtained in digital microwave relays for various uses.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional example. 201, 2θ2...phase modulation circuit, 301, 3
02...Transmitter, 401, 402--Fist receiver, 501, 502...Phase demodulation circuit.

Claims (1)

[Claims] In a method of transmitting control line signals using digital microwave multicarriers, the phase modulation circuit for each multicarrier performs frequency modulation using an independent control line signal for each of the multicarriers, and A control line transmission system characterized in that the frequency modulated signal is demodulated for each corresponding phase demodulation circuit, and each control line signal is obtained by the demodulation.