Channel coding method for low-density checking code

Abstract

The method includes following steps: the check matrix of low density check code is mapped into a geometrical body; the check matrix is built into four layers by using different threading method; each layer relates to a threading method in geometrical body; the check matrix built with four layer structure is converted into generator matrix by using Gaussian elimination method or triangularization method; the generator matrix is used in generating code word of code device. The check matrix is used in decode procedure of decoder.

Description

technical field [0001] The present invention relates to a channel coding method, in particular to a channel coding method based on a low-density parity check code based on geometric ideas. Used in the field of digital signal transmission. Background technique [0002] Compared with traditional channel coding, Low Density Check Code (LDPC code for short) has superior performance. In a communication system using LDPC codes, LDPC codes can be described by generator matrix and parity check matrix. At the sending end (encoder) of the system, the generator matrix is ​​used to generate codewords, and the parity check matrix determines the generation of the generator matrix; at the same time, the parity check matrix is ​​also directly used for decoding at the receiving end (decoder), so a An LDPC code can be completely determined by its check matrix, and the performance of the LDPC code also depends on the structure of the check matrix. The parity check matrix of the LDPC code is...

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Problems solved by technology

[0003] After searching the literature of the prior art, it was found that "Low-density parity-checkcodes based on finite geometries: A rediscovery and new results", (IEEE Transactions on Information Theory, November 2001, Vol. 47, pp. 2711 to 2736, Low Density Parity Check Codes Based on Finite Geometry: Some New Findings and Results). The generator polynomial generates the parity check matrix. Although this method completely avoids the occurrence of a ring with a length of 4, that is, the minimum ring length is 6 (the ring length must be an even number), but there are three problems in this method: (1) The minimum ring length is 6, the minimum ring length cannot be further increased, for example, a check matrix with a minimum ring length of 8 cannot be constructed

(2) The number of "1" in the parity check matrix is ​​relatively large, resulting in high hardware complexity of the LDPC decoder

(3) The code length and code rate are relatively fixed, which seriously limits its application in practical situations

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