Method and device for coding or decoding low-density parity-check (LDPC) codes with variable code length, coder and decoder

Abstract

The embodiment of the invention firstly provides a method for coding or decoding low-density parity-check (LDPC) codes with variable code length, which comprises the steps of: obtaining a base exponent matrix of the LDPC codes, and grouping code lengths during the construction of the base exponent matrix; modifying the base exponent matrix according to the grouped modifying factor to obtain a grouping exponent matrix corresponding to the grouped modifying factor; expanding the exponent matrix according to an expansion factor corresponding to the code length in the grouping to obtain an LDPC matrix corresponding to the code length; and coding or decoding according to the LDPC matrix. By adopting the method for coding or decoding the low-density parity-check (LDPC) codes with variable code length and adopting grouping and repeatedly constructing, the obtained LDPC codes do not have short links at each required code length, and the performance is greatly improved. Meanwhile, the embodiment of the invention also provides a device for coding or decoding, a coder and decoder.

Description

technical field [0001] The present invention relates to the technical field of error correction coding for communication and information systems, in particular to a method and device for coding or decoding variable code length low-density parity check codes, as well as an encoder and a decoder. Background technique [0002] Low density parity check (LDPC, low density parity check) code is a linear block code proposed by Gallager in 1962. Because of the small number of "1" in its parity check matrix, it is called low density parity The checksum was then reintroduced and improved upon by Mackay in 1996. In addition to expressing LDPC codes with parity check matrices, Tanner graphs can also be used (see figure 1 ) represents an LDPC code, and the Tanner graph corresponds directly to the check matrix, which consists of variable nodes, check nodes and edges connecting them. Each check node z i Corresponding to row i of check matrix, each variable node x j Corresponds to the j...

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Problems solved by technology

[0005] However, the current implementation either only supports the case where the code length grows by an integer multiple, or there are too many restrictions in the construction process, resulting in the performance of the LDPC code supported by a matrix at the required code length and the independent design. far from performance

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