A code word construction method of ldpc code

Abstract

The present invention discloses a codeword construction method of an LDPC code, comprising the following steps: Step 1, setting the size of the parity check matrix of the LDPC code, including setting the number of rows, the number of columns, and the size of the cyclic sub-block of the parity check matrix . Step 2, according to the number of rows, the number of columns and the size of the cyclic sub-block, calculate the number of cyclic sub-blocks contained in the parity check matrix, and search for an optimal row and column degree distribution, which uniquely determines each cyclic sub-block The column degree value; The code table of the LDPC code is set so that each cyclic sub-block corresponds to a corresponding row in the code table, and the number of numbers in the corresponding row is equal to the column degree value of the cyclic sub-block. Step 3, determine the value of each number in the code table. The code word constructed by the present invention is an irregular code word, and the design of the column weight distribution and the elimination algorithm of the short ring make the code word performance close to the Shannon limit, and the design of the double diagonal form degree 2 nodes simplifies the realization of the encoder, and the row weight Regularization considerations can reduce the error floor of a codeword.

Description

technical field [0001] The invention relates to a method for constructing codewords, in particular to a method for constructing codewords for LDPC codes. Background technique [0002] The LDPC code was first proposed by Gallager in his doctoral dissertation in 1963. At the same time, Gallager also proposed the probabilistic decoding algorithm of the LDPC code. However, due to the complexity of the probabilistic iterative decoding calculation, it was difficult to realize the technical development level at that time, so LDPC The code quickly disappeared in the communication world at the time. Afterwards, except for Tanner who used a bipartite graph to describe iterative decoding in the 1980s, few scholars paid more attention to LDPC codes. [0003] In 1993, the proposal of Turbo code made people see a coding scheme that can approach the Shannon limit for the first time after 45 years. So far people have begun to notice the excellent performance of iterative decoding. At the ...

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Problems solved by technology

[0005] However, due to the late development of LDPC, it missed the third-generation mobile communication. However, in the future 4G mobile communication standard IEEE 802.16m and the new generation of digital TV terrestrial standards in North America, LDPC will be a strong competitor

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