Method for constructing code-rate compatibility QC-LDPC code

Abstract

The invention relate to the technical field of channel coding of a wireless communication system and a satellite communication system, and provides a method for constructing a code-rate compatibility QC-LDPC code on basis of matrix row deletion. The method includes the steps that firstly, on the basis of a GCDg8 algorithm, QC-LDPC codes with a large girth and a low code rate are constructed to serve as primary codes, then successive row deletion of an exponential matrix is carried out to obtain subcodes with a high code rate and an unchanged information bit length, and the short-length problem of code words with a high code rate is avoided; row deletion means that corresponding edges of Tanner graphs corresponding to the primary codes without the short-length problem are deleted, the short-length problem cannot occur, and the girth may increase; ultimately, the subcodes are processed through a hidden technique, the minimal distance of the code words is increased, and performance of the code words is improved. According to the method, the code-rate compatibility QC-LDPC code with structural design is adopted, and compared with an LDPC code constructed in a PEG algorithm, construction is easier to achieve, hardware achievement complexity is not high, and performance is more excellent.

Description

technical field [0001] The invention relates to the technical field of channel coding of a wireless communication system and a satellite communication system, in particular to a construction method of a rate-compatible QC-LDPC code. Background technique [0002] Different from the channel coding technology of traditional wireless and satellite communication systems, low-density parity-check (Low-Density Parity-Check, LDPC) code is a kind of linear block code defined by sparse parity check matrix, using belief propagation (belief propagation, BP) algorithm decoding, not only has good performance close to the Shannon limit, but also has low decoding complexity and flexible structure. It is a research hotspot in the field of channel coding in recent years. Satellite digital video and audio broadcasting and other fields. [0003] In recent years, researchers have found that the introduction of rate-compatible LDPC code coding technology under the time-varying channel conditions...

AI Technical Summary

Problems solved by technology

Although this method can avoid the disadvantage of deteriorating subcode decoding performance during the puncturing process, the expansion process is equivalent to adding new check nodes, variable nodes, and edges corresponding to new non-zero elements in the corresponding Tanner graph. , so it is necessary to consider avoiding the newly added non-zero elements to generate new short cycles in the corresponding Tanner graph, thus increasing the complexity of the degree distribution optimization in the expansion process

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