SU588639A1 - Method of monitoring the level of multiple transmission system individual analogue channels - Google Patents

Description

and estimate the mutual correlation of the sum signal and the measurement frequency signal.

With this method, the control oscillation of the lower level on the transmitting side is produced by dividing the oscillation produced by the system, whose frequency lies in the range of transmitted frequencies; the frequency of the control low-level oscillation lies in the low-frequency transmission range, and the control oscillation of the lower level is processed and transmitted together with the communication signal. At the receiving side, the sum signal from the communication signal and the control oscillation of the lower level are mutually correlated by the same frequency oscillation produced by the receiving side.

For a temporary compression transmission system, the measurement frequency is derived from the binary cycle of the fundamental frequency.

For a frequency-multiplexed transmission system, the measurement frequency is derived from the control oscillation of the linear path.

The proposed method has several advantages. Current level monitoring, both in the form of continuous observation and at selected intervals, is possible during normal operation, and as a result, communication channels are better utilized.

The limitation of the bandwidth of the communication signal is eliminated and the technical cost of measurement is reduced. For mutual correlation, existing or simplified correlators are applicable. No additional measurement line is required, as a result, the free channel is not occupied, which further improves the use of communication channels.

FIG. 1 shows a structural electrical transmission system with pulse code modulation, with a level control device; in fig. 2 is a structural electrical circuit diagram of a transmission system with a carrier frequency, with a level control device.

A controlled transmission system with pulse code modulation (CMM) consists, according to FIG. 1, from the end point 1 of the CIM of the transmitting side, the linear path 2 of the CIM and the end point 3 of the CIM of the receiving side. At the end point 1 of the transmitting side, the communication signals of the px LS channel channels are jointly connected to the temporarily-compressed signals. The time division rhythm in the CIM transmission system is established using the binary cycle of the fundamental frequency F-B.

On the receiving side of the 3 CMM end point, a low-frequency analog signal is returned from the temporarily compressed signal coming in along the linear path 2 and distributed on the receiving side, respectively, on the n telephone channels Le.

The device control level on the transmitting side contains the transmitter 4 control lower level, which consists of

two dividers 5, 6 frequency amplifier 7 and the distributor 8. The input of the frequency divider 5 is connected to the output terminal point 1 of the transmitting side, one output - to the input

amplifier 7 and the other output with the input of frequency divider 6, the output of frequency divider 6 is connected to the control input of the distributor 8. The level processing device 9 consists of a push-pull return device 10, which already exists inside or outside the receiving side of the end point 3 of the CMM, sequentially a frequency divider 11 connected to it, a subsequent amplifier 12, a phase shifter 13, a mutual correlator of torus 14, a threshold circuit 15, a frequency divider 16, an alarm control unit 17 and a distributor 18. The second output of the frequency divider 11 It comes with a divider 16 frequency input, and the last output is with a block input

17 control sync. The output of the synchronization control unit 17 is connected to the control input of the distributor 18, and its other output is connected to the end point 3 of the CMM. Phaser 13 is turned on after the amplifier.

12 and its output is connected to the input of the mutual correlator of the torus 14. The output of the correlator of the torus 14 goes to the input of the threshold circuit 15.

The two-stroke fundamental frequency F coming from the end point 1 of the CMM in the frequency divider 5 is divided into a measuring P

frequency FM oscillation to

by means of amplifier 7, it is brought to the level of the lower frequencies required for connection to the channels, and by means of the distributor 8 is distributed on n separate low-frequency telephone channels. Frequency

current parcels Р-е -5- are produced

rr

the frequency divider 6 and in time with it the amplifier 7 is turned on. The control oscillation of the lower levels is added to the communication signal and is supplied to the terminal point 1 of the transmitting side CMM. Of the latter

the pulse-modulated signal is transmitted through the linear path 2 to the receiving side of the terminal point 3. From the push-pull return device 10, the push-pull fundamental frequency Pb is supplied to frequency divider 11 and the latter is divided by the measuring frequency Pf -

The measurement frequency for the first time in the second frequency divider 16 is divided by the frequency of the current parcels P-e and the second time through the amplifier 12 and the phase shifter 13 is supplied to the mutual correlator 14 in the Zin waveform. The distributor 18 is synchronized with the distributor 8 to the clock frequency of the current parcels Ff by the synchronization control unit 17 to the station side of the low frequency telephone channels. The summed signal Y from the control oscillation of the lower level and the communication signal, read by the distributor 18, is last supplied to the second

the input of the correlator of the torus 14. The initial value of the tr of the correlator of the torus 14 is obtained from the relation:

t

6 lira-IT Z (f) -Y (f) di,

r-co 2G J

where T is the integral time,

Y is the transmitted total signal received at the receiving side of the end point, from the oscillation of the control low level with the measuring frequency / m and the communication signal, ZM is the oscillation with the FM frequency at the input

correlle torus.

Tjj represents the attenuation value between the input of the transmitting side of end point 1 and the output of the receiving side of end point 3 of the CMM.

The threshold circuit 15 signals in the usual manner an over tolerance. If both distributors 8, 18 stop, then the level control device is activated for continuous monitoring. In this mode of operation, the threshold alarm can be replaced by self-scanning.

For transmission systems with a carrier frequency, as shown in FIG. 2, similar relationships are obtained. The end point 19 of the carrier side of the transmitting side is connected via a linear path 20 of the carrier frequency to the end point 21 of the carrier frequency of the receiver side. Similarly, the transmitter 22 of the control lower level from end point 19 provides the frequency fp of the linear control oscillation of the carrier frequency to obtain the measurement frequency, respectively, of the control oscillation of the lower level.

The frequency of the control linear oscillation of the carrier frequency is returned to the level processing device 23 by the reference filter 24. The control filter 24 may be located inside or outside the end point 21. Otherwise, the level processing device is constructed similarly to that shown in FIG. one.

The principle of operation of the checking device according to FIG. 2 is similar to that shown in FIG. 1. The ratio divider for generating the measurement frequency Pj varies accordingly.

Claims (2)

1. Siemens Zeitschrift, No. 42, 1968, p. 710- 713, Berlin. 2.AEU, No. 15, 1961, Berlin, p. 437-443. I . I