SU1688432A1 - Radio channel discrete signals distortion tester - Google Patents

Description

one

(21) 4737547/09

(22) 11.09.89

(46) 10/30/91. Bul №40

(72) N.P.Galkin

(53) 621.396.664 (088.8)

(56) USSR Copyright Certificate No. 1578822, cl. H 04 B 17/00, 1989.

(54) DEVICE FOR CONTROLLING DISTORTIONS OF DISCRETE SIGNALS IN RADIO CHANNELS

(57) The invention relates to telecommunications. The purpose of the invention is to improve the accuracy of control by taking into account the sign of a false time shift between two partial

channels. The device contains blocks 1.1 and 1.2 of the reference phase, triggers 2 and 10, elements 3 and 12, master oscillator 4, reversible counter 5, decoder 6, memory register 7, comparator 8, element OR 9, indicator 11 time shifts and sensors 13 and 14 code number. The magnitude of the shift between the reference phases at the outputs of blocks 1.1 and 1.2 is fixed by the reversible counter 5, and the sign of this shift is triggered 10. The data obtained through the register 7 is displayed by the indicator 11, which also displays the alarm signal when the comparator trips 8. 1 Il.

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The invention relates to telecommunications and can be used in equipment for measuring and controlling distortion of discrete signals in a multi-channel transmission system.

The purpose of the invention is to improve the accuracy of control by taking into account the sign of a false time shift between two partial channels.

The drawing shows a block diagram of the proposed device.

The device for monitoring distortion of discrete signals in radio channels contains the first and second blocks 1.1 and 1.2 of the reference phase, the first trigger 2, the first element AND 3, the master oscillator 4, the reversible counter 5, the decoder 6, the memory register 7, the comparator 8, the element OR 9 , the second trigger 10, the indicator 11 time shifts, the second element And 12 and the first and second sensors 13, 14 code number.

The device works as follows.

Discrete signals of the K-th and r-th partial channels (g K) after their detection are fed to the inputs of the first and second blocks 1.1 and 1.2 of the reference phase, respectively, which produce pulses with a period T0, the temporal distortion of which corresponds to the mathematical expectation of the characteristic moments tion (sign of the exchange of parcels). In data transmission systems, when splitting the flow of information on the transmitting side into n partial channels, the information of each subsequent channel number

lags behind the previous one on TV - where TV is the duration of sending a high-speed source of information. In the ideal case, at the receiving end, in the absence of false time shifts in the channels, due to different instabilities, the reference phases of the signals at the outputs of the reference phase blocks 1.1 and 1.2 are also shifted by the time Tv, and the reference phases of the Kth and rth channels by ( d - C) TV. In radio channels, besides these deterministic shifts, random (parasitic, false) time shifts take place both in the direction of advance and lag. If false time shifts on the transmitting side are mainly due to instrumental instability, then at the receiving end the main factor of the appearance of false shifts conditions of propagation of radio waves and hardware instability.

The signals of the reference phase from the outputs of the first and second blocks 1.1 and 1.2 of the reference phase are received respectively at the inputs

set and reset trigger 2. which generates a signal whose duration is equal to the time shift between the reference phases of the K-th and r-th channels. Without

false time shifts in the channels, the duration of the pulses at the output of trigger 2 will be equal to (r - K) TV. Since the channel lagging behind the constant time shift from the previous channels by the time g 0.5 T0

at the same time is leading

time T0 - d, then for (g - K) j r-th channel

should be connected to the input of the first block 1.1 of the supporting phase, which provides for the conditional 6 0.5 T0, and the calculation of the time shifts in this case is determined by the expression n - (g - K) TB. When the reference phases in the channels oscillate, the pulse duration at the output of trigger 2 will vary from zero to T0.

If the pulse duration is in the range of (g - K) Tv to (g - K) Tv + 0.5 T0, t j the shift of the reference phase in the second channel will be in the direction of lag (for the case of (g - K): -).

If the pulse duration is in the range from 0 to (g - K) TV and from (r - K) TV + 0.5 T0 to T0, then the shift of the reference phase in the second channel will be in the direction of advance.

The signal from the output of the trigger 2 is fed to the input of the first element I 3. The second input of which receives pulses from the output of the master oscillator 4 with a period equal to 1% of T0 (at T0 5 ms the frequency of the generator

equal to 20 kHz). The counting pulses from the output of the first element And 3 arrive at the counting input of the binary-decimal reversing counter 5, which works on the addition from 0 to 50, after which it switches to.

subtraction from 50 to 0. To the inputs of the preliminary recording of the reversible counter 5 from the first sensor 13 of the code number the number No is given in the binary-decimal code corresponding to the regular shift (r - K) Tv

(or n - (r - K) TV). As the first sensor 13 of the code number, a ROM (read only memory) can be used in which time shifts are recorded for any pair of partial channels. This number is recorded in the reversible counter 5 by the reference signal of the first block 1 1 of the reference phase, which enters the input of the reversing counter 5. The signals from the information outputs of the reversible counter 5 are fed to the inputs of the decoder 6, the memory register 7 and the first inputs of the digital comparator 8.

The decoder 6 generates signals at its outputs for the numbers 0 and 50 at the outputs

reversible counter 5. From the output of the decoder 6 signal number 50 through the element OR

9 arrives at the reset input of the trigger 10, and the signal of the number 0 - to the input of the trigger 10, from the output of which the signal 0 or 1 is fed to the input of the reverse ± reversing counter 5. If the signal at the trigger output

, the reversible counter 5 works on addition, and if O - on subtraction. In addition, the reset input of the trigger 10 through the element OR 9 receives the signal of the reference phase from the output of block 1.1. Thus, with the occurrence of the measuring pulse at the output of trigger 2 in the reversible counter 5, the code number No and the subtraction mode are set. In the absence of distortions, at the end of the measuring pulse in the reversible counter 5, the number 0 will be recorded, and in the presence of distortions - different from 0. The signal of the reference phase of the delayed channel overwrites the magnitude of the distortion from the output of the reversible counter 5 and the sign of the distortion from the output of the trigger 10 in register 7 the memory, from the output of which information about the sign and magnitude of the false time shift is fed to the inputs of the indicator, 11 time shifts. When using a device for periodic monitoring at the receiving end of a radio link, of interest are temporal shifts between channels with a threshold value of 0.4 T0. A crash signal for such shifts is generated by a digital comparator 8, the second inputs of which from the second sensor 14 of the code number receive the code number B 40. If at the moment of the end of the measuring pulse from the trigger output 2 the number in the reversible counter 5 exceeds the number B, then the output a comparator 8 appears signal 1, which is fed to the input of the second element And 12. In this case, the signal from the output of the second block 1.2 of the reference phase through the second element 12 is fed to the input of the indicator 11, indicating the signal of Avari, and

also the sign and magnitude of the false time shift between the channels.

Claims (1)

Claims An apparatus for monitoring discrete signal distortions in radio channels, comprising the first and second blocks of the reference phase, the OR element, the master oscillator, the first trigger and the first I element connected in series. The successively connected reversible counter, the memory register and the time shift indicator, and the serially connected decoder whose inputs are connected to the corresponding outputs of the reverse counter, and the second trigger, characterized in that, in order to increase the accuracy of the control by taking into account the sign of a false time shift between two partial channels, the second element I is entered into it, comparator and the first and second code number sensors, while the second output of the decoder through the OR element is connected to the reset input of the second trigger, the output of which is connected to the corresponding input of the memory register and to the reverse input of the reversible counter, the preliminary recording inputs and outputs of which are connected respectively to the outputs the first sensor of the code number and the first inputs of the comparator, the second inputs and outputs of which are connected respectively to the outputs of the second sensor of the code number and to the first input of the second element And whose output is connected to the alarm input indicator of time shifts, the output of the master oscillator is connected to the second input of the first element I, the output of which is connected to the counting input of the reversible counter, and the output of the first block of the reference phase is connected to the input of the reversible counter recording, to the second input of the OR element and to the installation input of the first trigger, the reset input of which is connected to the output of the second phase support unit, to the second input of the second element AND and to the recording input of the memory register.