SU1555884A1 - Method of restoring stereo digit signal coded with code detecting error units, duration not exceeding n symbols - Google Patents

Abstract

The invention relates to radio engineering and communications. The purpose of the invention is to improve the accuracy of the recovery of a stereo digital signal (DSS). The essence of this method of restoring DSS is explained by a device containing two channels, on the corresponding input buses of which a broadcasting DSS arrives, having errors of a different type and representing a sequence of code words. This DSS is converted in two channels, consisting of error detection blocks 1 and 2, error counters 3 and 4, drivers 5 and 6, delay blocks 7, 8, 9 and 10, transfer blocks 11 and 12, memory blocks 13 and 14 and blocks 15 and 16 of the formation of the mark. After detecting an error block in one of the channels, the goal is achieved by transferring the delayed signal of the second (first) channel to the first (second) channel with a sign formed in the first (second) formation unit. 1 il.

Description

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The invention relates to radio engineering and communications and can be used in digital broadcasting and sound recording systems.

The aim of the invention is to improve the accuracy of the recovery of a stereo digital signal.

The drawing shows a structural electrical circuit of the device implementing the method.

The device contains the first 1 and second 2 error detection blocks, the first 3 and second 4 error counters of the first 5 and second 6 drivers,

and even

the first 7, the second 8, the third 9, the last 10 delay blocks, the first 11 and second 12 transfer blocks, the first 13 and second 14 memory blocks, and the first 15 and second 16 blocks of sign formation.

The method is as follows.

A digital broadcasting stereo signal, having errors of a different type and representing a sequence of code words, arrives at the corresponding input buses of the first and second channels. In each of the channels, the first 1 and second

2 blocks at the end of the next cycle detect any errors. From the output of the first (second) block 1 (2, the signal goes to the first (second) counter 3 (4) errors, which counts their number. A number equal to the calculated number of errors from the output of the first (second) counter

3 (4) is fed to the first input of the first (second) driver 5 (6), the second input of which is supplied from the output of the first (second) unit 1 (2). The shaper 5 provides the formation of control signals — transfer signals with a duration equal to the duration of the detected error block and a definable number at the first input, with the front of the signal at the output relative to the front of the signal

appears at the first input after a time equal to the difference between the maximum and the actual duration of the error block.

In addition, the input signal is fed to the first (second) block 7 (8), in which it is delayed by the time of the maximum error block duration, increased by the period of the code words, the delayed signal is output from the output of this block

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as the first information input of the first (second) unit 11 (12), and the input of the third (fourth) unit 9 (10).

In the third (fourth) block 9 (10), the delayed signal is additionally delayed by the duration of the codeword time period. From the output of the third (fourth) block 9 (10), the signal is fed to the information input of the first (second) block 13 (14), to the control input of which the transfer signal from the output of the first (second) imager 5 (6) is fed. During the first clock interval defined by the edge of the transfer signal, in the first (second) block 13 (14) the sign of the signal arriving at the information input is remembered and output from the output to the first control input of the first (second) block 15 (16) logical O, if the signal is negative, or logical 1, if the signal is positive;

At the same time, the information input of the first (second) block 15 (16) receives a signal from the output of the second (first) block 8 (7), the sign of which is the same at the output, if the sign of the first relative to the transfer signal acting on the second control input is the code word coincides with the memorized sign and the opposite otherwise. From the output of the first (second) block 13 (14), the signal goes to the second information input of the first (second) block 15 (16), to the control input of which a delayed transfer signal is fed, and the information from the second information block is transferred to the output of the corresponding transfer block. the entrance. In this way, the delayed signal of the second (first) channel is transferred to the first (second) channel with the sign formed in the first (second) block 15 (16) of the sign formation.

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Claims (1)

Invention Formula A method for reconstructing a stereo digital signal encoded with a code that detects error blocks with a duration of no more than N symbols, consisting in receiving a stereo digital signal on two channels, detecting error blocks in each channel and measuring their duration M, forming a transfer signal, in duration equal to the duration of the error block and delayed relative to the block of errors for a time equal to (M-M) Ј, where t is the duration of the characters of a stereo digital signal, and stereo digital The second signal in each channel is successively delayed by the time NЈ + T, where T is the period of the following words of the stereo digital signal, and by the time T, in a row, so that, in order to improve the accuracy of the recovery of the stereo digital signal, after detecting a block of errors five in one of the channels, for the duration of the transfer signal in this channel, the polarity of the stereo digital signal delayed by the time NЈ + T in the other channel is determined and stored in the first channel for the duration of the transfer signal the stereo digital signal delayed by NT + 2T, replaced by a stereo digital signal; of the channel delayed at the same time with the polarity of the stereo digital signal of the first channel, if it coincides with the stored polarity of the other channel or with the pro- opposite polarity otherwise.