Construction method for quasi-cyclic low density parity check (LDPC) code check matrix

Abstract

The invention relates to a construction method for a quasi-cyclic low density parity check (LDPC) code check matrix. The construction method for the quasi-cyclic LDPC code check matrix comprises the following steps of: determining a line parameter J and a column parameter L of a basis matrix of the check matrix to be designed; after the line and column parameters are determined, traversing all columns by the line, and for the given position of the jth line and the lth column of the basis matrix, sequentially obtaining terms of each Hanoi tower array according to the definitions of the Hanoi tower array that f(1)=1 if n is 1 and that f(n+1)=s*f(n)+1 if n is more than 1; obtaining a circulant permutation matrix offset value pj,l according to a formula pj,l=f(j+1)+j, adding a digital value jof a corresponding line to each f(j+1) value obtained by the second step to obtain a circulant permutation matrix offset value pi,j and arranging the pi,j at the position of the jth line and the lth column of the basis matrix to be constructed; and constructing the basis matrix to be designed by using all the pj,l values. By the method, the performance of a quasi-cyclic LDPC code is improved, and simultaneously storage complexity is decreased.

Description

technical field [0001] The invention belongs to the technical field of communication, in particular to a method for constructing a check matrix of a quasi-cyclic LDPC code. Background technique [0002] LDPC code is Low Density Parity Check Code (Low Density Parity Check Code, LDPC), which is a kind of linear block code with sparse parity check matrix proposed by Robert G. Gallager. Afterwards, MacKay and Neal et al. re-studied LDPC codes and proposed a feasible decoding algorithm for LDPC codes, thus further discovering the good performance of LDPC codes. [0003] At present, LDPC codes have been widely used in deep space communication, optical fiber communication, satellite digital video and audio broadcasting and other fields. LDPC code has become a strong competitor of the fourth generation communication system (4G), and the coding scheme based on LDPC code has been adopted by the next generation satellite digital video broadcasting standard DVB-S2. [0004] Random LDP...

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Problems solved by technology

[0008] The analysis found that its check matrix storage complexity is JL, and the LDPC code is randomly constructed. It still has a high storage complexity. At the same time, this scheme does not reflect the performance of the LDPC code close to the Shannon limit. The main reason is that there is no effective control of the short loop with a length of 4.

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