Construction method and encoding method for check matrix of LDPC code

Abstract

The invention belongs to the construction technology field of LDPC code (low-density parity-check code) check matrix, and in particular relates to a construction method and encoding method for check matrix of LDPC code. The construction method for check matrix of LDPC code comprises the steps as follows: building the base matrix HB of the LDPC code check matrix, aiming at the base matrix HB, detecting and eliminating the four ring to obtain the base matrix after removing the four ring; in the base matrix after removing the four ring, using z*z whole zero matrix for replacing the 0 element, z expresses the set extension factor; F expresses the number of the non-zero element in the base matrix after removing the four ring, HB(f) expresses the f(th) non-zero element in the base matrix after removing the four ring, obtaining the matrix Iz(HB(f)) of the unit matrix with size of z*z for ring shift right of HB(f), in the base matrix after removing the four ring, replacing the f(th) non-zero element HB(f) by the matrix Iz(HB(f)); obtaining LDPC code check matrix, the LDPC code check matrix is the new matrix after replacing each element for the base matrix after removing the four ring.

Description

technical field [0001] The invention belongs to the technical field of LDPC code (low density parity check code) check matrix construction, and in particular relates to a construction method and an encoding method of a check matrix of an LDPC code. The present invention aims to construct a quasi-cyclic LDPC code check matrix with simple structure and easy storage Background technique [0002] With the development of society, digital communication has become an indispensable part of people's life and has a wide range of application scenarios. The most well-known communication includes wireless communication, satellite communication, digital TV, digital broadcasting, wireless network, video on demand and so on. In addition, there is an abstract "communication" method, that is, a data storage system, and its typical applications include disks, tapes, CD / DVD, etc. For data storage systems, communication is the "transfer" of useful information from one point in time to another....

AI Technical Summary

Problems solved by technology

[0004] The shortcomings of the construction scheme of the check matrix of the LDPC code in the prior art mainly include: the check matrix is ​​not easy to store, the code length / code rate cannot be flexibly changed, and the encoding efficiency is low

For example, due to the pure randomness of the matrix obtained by the random construction method proposed by Gallager, the complexity of encoding is greatly increased, and a large storage space is required for matrix storage.

The PEG algorithm obtains a lower triangular matrix. Although this structure can reduce the coding complexity, the matrix is ​​still random, and it also requires a high storage space for the device, which is not conducive to hardware implementation.

The check matrix based on finite fields and finite geometry has a rigorous algebraic structure and has cyclic or quasi-cyclic characteristics (any row in the matrix is ​​a cyclic right or left shift of the previous row), thus greatly reducing the requirements for hardware storage space , however, since the matrix is ​​constructed based on finite fields and finite geometries, the code length and code rate of this type of code cannot be flexibly changed

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