Method and codec for rate-compatible low-density parity-check code

Abstract

The invention discloses a speed-compatible and low-density parity check code coding and encoding method and a codec. The method comprises the following steps: determining a first mother matrix corresponding to a code with the highest code rate; using a PEXIT algorithm to reduce a decoding threshold according to the first mother matrix, and calculating second mother matrixes corresponding to codeswith low code rates; calculating basis matrixes corresponding to the codes of the code rates based on the principle of the least short loop number of the matrixes according to the first mother matrixand the second mother matrixes; performing matrix extension processing on the basis matrixes to obtain a check matrix of speed-compatible and quasi-cyclic low-density parity check codes; and performing coding or decoding according to the check matrix of the speed-compatible and quasi-cyclic low-density parity check codes. By adoption of the method provided by the invention, based on the principleof the lowest decoding threshold and the least short loop number of the matrixes, the flexibility and the error correction performance of the speed-compatible and quasi-cyclic low-density parity checkcodes are improved.

Description

technical field [0001] The invention relates to the technical field of error correction coding for communication and information systems, in particular to a method for encoding and decoding rate-compatible low-density parity-check codes and an encoding and decoding device. Background technique [0002] Communication channel environments typically have time-varying properties. In time-varying communication channels, using rate-compatible (RC) error-correcting codes is one of the effective ways to improve system throughput and reliability. A set of rate-compatible error correction codes includes multiple codes with different code rates. The code word bits of the high code rate code are embedded in the code word bits of the low code rate code. A pair of encoders and decoders can be used for encoding. , decoding. When the time-varying communication channel is reliable, a code with a higher code rate is used to obtain higher system throughput, and when the reliability of the ti...

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Problems solved by technology

The extension method takes the code with the highest code rate as the mother code, and gradually increases the check bits of the code with a high code rate to obtain a code with a lower code rate. It can be based on the algebraic construction method and the graphical model-based construction method. Through the extended idea A structured RC-LDPC code that can be quickly encoded is designed, but when the RC-LDPC code is constructed by the above-mentioned extension method, each Z j (1≤j≤J) have the same dimension, both are m 1 ×n 1 , the available code rate is R j =k / (n 1 +(j-1)m 1 ), (1≤j≤J), the flexibility of the code rate is limited, that is, once the highest code rate is determined, the remaining code rates are limited; and Z j The jth column of is either an all-zero column, or the same as Z 1 The jth column is the same, which limits the selectable modes, and the bit error rate is high

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