SU1210141A1 - Device for reproducing digital messages - Google Patents

Abstract

The device relates to the field of magnetic recording. The purpose of the invention is to reduce the error in reproducing digital messages by increasing the likelihood of error detection. The device contains a detecting unit 1, lags 11 and 2, a shift register 3 and a buffer register 4, a code converter 5, a recording unit 6, a storage device 7, decoders 8 and 9, an output register 10, a delay element 15. New is that the device contains the OR elements and NOT 13 and 14, and the code converter 5 is made with an additional output connected via the HE element 14 to one input of the OR 13 element connected to the second output of the detection unit 1 and the output to the detector's marking input 8. 1 Il. (L Preo / zozobotel r1 L: i. D1HE / g Fn ff

Description

This invention relates to magnetic recording, in particular to devices for reproducing digital messages.

The purpose of the invention is to reduce the error in reproducing digital messages by increasing the probability of detecting an error.

The drawing shows a functional diagram of one of the possible variants of the device for reproducing digital communications.

The device for reproducing digital messages contains a detecting unit 1 connected by an input to input bus 2 and a first output via shift register 3 to an input of buffer register 4 connected by outputs with inputs of converter 5 of the code, outputs through block 6 of registers connected to inputs of a buffer memory 7, the first 8 and second 9 decoders and the output register 10, the output of which is connected to the output bus 11, and the marking output of the first decoder 8 is connected through the first delay element 12 to the marking input the second decoder 9. In addition, the device contains the OR elements and NOT 13 and 14 and the second delay element 15, and the code converter 5 is made with an additional output connected through the element 14 to one input of the OR element 13 connected by another input to the second output block 1 detection and output through the second delay element 15 to the marking input of the first decoder 8.

A device for reproducing digital messages operates in the following manner.

The signal received from the message channel is demodulated by the detection unit 1 into a sequence of channel code elements. In the presence of erasing, the detection unit 1 generates a marking signal at the second output, and zero channel code elements are formed at the first output. The marking signal through the element OR 13 enters the first decoder 8, and the signal of the channel code passes to the shift register 3, in which the serial channel code is converted into parallel. When accumulating in register 3 a complete combination of a channel code, it is rewritten into a buffer register 4, and then converted by the converter 5 of the code into the corresponding code symbol. marking signal. Non-working combinations are detected by fixing the zero character code at the output of converter 5, provided that the channel code combination at the input of the converter 5 of the code is different from the combination corresponding to

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left character. Thus, for each forbidden, non-working combination of the redundant channel code, the code converter 5 generates the corresponding CHMBOvTbi marking signals, characterizing these symbols as erroneous.

From the output of the code converter 5, the code symbols go to register block 6, where they accumulate and from where they are written to buffer memory 7 at a constant clock frequency. Buffer register block 6 is used to compensate for irregularities in the flow of code symbols from the channel, and buffer memory 7 serves for interleaving code symbols to correct error packets. From the buffer memory device 7 with fixed delay times, the code symbols are transmitted block by block to the first decoder 8, where simultaneously from the output of the second element 15 the marking signals corresponding to these symbols are received. The first decoder 8, on the basis of calculating and analyzing syndromes and taking into account marking signals, determines the presence of error symbols in the code block (before interleaving), corrects them, and sends them corrected back to the buffer memory 7. With a large number of errors and impossibility of their localization and correction in the first decoder 8, the latter returns uncorrected symbols to the buffer memory 7, but at the same time for all the code block symbols, as unreliable, sends to the first element 12 delays marking signals s. In the second decoder 9, the symbols (after interleaving) are also received block by block from the buffer memory 7 and also with fixed delay times determined by the adopted interleaving law. At the same time, the second decoder 9 receives from the first delay element 12 delays the marking signals corresponding to these symbols. Like the first decoder, the second decoder 9 determines the presence of symbols with errors in the code block, corrects them, and transfers the corrected signals to the buffer memory 7, from which the sequence of characters is very a low probability of having errors in them is transmitted to the consumer of the messages.

The use of the invention significantly increases the fidelity of reproducing digital messages.

Claims (1)

Invention Formula A device for reproducing digital messages comprising a detecting unit connected by an input to an input bus and a first output through a shift j1210141d register to the input of the buffer register, error co-detection, elementalized outputs with the OR and NOT conversion inputs are entered into it, and the code-breaker code converter, outputs connected to an integrated output with an additional output, the coupling inputs of the decoder, the output through item NOT with one input The latter is connected to the output bus from the OR-element connected to another in such a way that, in order to reduce home to the second output of the detecting unit, the digital reproduction and the output to the marking input of the messages by increasing the likelihood of the coder.