Fast multivariate LDPC code decoding method with low decoding complexity

Abstract

The invention discloses a fast multivariate LDPC code decoding method with a low decoding complexity, belonging to the technical field of mobile communication channel coding. According to the multivariate LDPC code decoding method, when storing decoding messages, only the decoding messages corresponding to the location of a non-zero element in a check matrix H are stored, and due to the sparsity of the check matrix H, the decoding method can greatly reduce the storage space occupied by the decoding messages when being implemented by using software or hardware. During decoding, the addressing speed of the decoding messages can be accelerated by using pre-calculated information of the non-zero element in the check matrix H, wherein the information includes the row number, the column number and an element value of the non-zero element; and meanwhile, in a decoding iteration process, fast Fourier transform is introduced to reduce the complexity of a decoding operation when processing a check node message, and thus the decoding speed can be accelerated. The decoding method disclosed by the invention has a relatively low decoding complexity, requires a small storage space, and can also increase the decoding speed to a great extent.

Description

technical field [0001] The invention relates to a fast multivariate LDPC code decoding method with low decoding complexity, belonging to the technical field of mobile communication channel coding. Background technique [0002] With the development of communication technology and the needs of practical applications, people are constantly looking for channel coding methods that can approach the Shannon limit. In 1962, Gallager proposed the LDPC code for the first time, and then MacKay and others found that the error correction ability of the LDPC code has the advantages of approaching and possibly surpassing the Turbo code under the condition of low coding and decoding complexity, so the LDPC code appeared. The research upsurge has become the most eye-catching hotspot in the field of channel coding today. [0003] In 1998, Mac Kay and Davey proposed a multivariate LDPC code based on multivariate field GF(q) for the first time in the article "Low Density Parity Check codes ove...

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Problems solved by technology

However, since the operation in the multivariate field is not as simple as that in the binary field, the decoding complexity of the multivariate LDPC code increases sharply with the increase of the order of the multivariate field, which limits its practical application. The processing of multivariate LDPC codes is the most complex part in the decoding process of multivariate LDPC codes, so the decoding complexity of multivariate LDPC codes is higher than that of binary LDPC codes

[0004] The Tanner graph has a strong correspondence with the check matrix H of the LDPC code. Usually, the number of decoded messages stored during decoding is the same as the dimension of the check matrix H of the LPDC code, where the dimension of the check matrix H is is M×N, usually the dimension of the parity check matrix is ​​very large, which means that a large amount of storage space will be wasted by using the traditional way to store the decoding message

Moreover, the storage space used will increase sharply with the increase of the LDPC code length, which is not conducive to the realization of software and hardware.

Since each multi-ary code unit is composed of multiple binary code units, compared with the decoding of binary LDPC codes, the decoding of multi-ary LDPC codes becomes more complicated, and the amount of decoding calculations has increased significantly.

The decoding message storage method used in the paper "Research on Coding and Decoding Algorithms of Multi-ary Quasi-Cyclic LDPC Codes" [Harbin Engineering University, Zhang Han, Master's Thesis, 2013.03] is as described above, and a lot of time will be wasted during decoding. storage space, and the storage space used will increase sharply with the increase of the LDPC code length; the traditional decoding method used in the paper is complicated to decode and has a large amount of calculation, which is not conducive to the realization of fast decoding

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