Low density odd-even check code iterative sequencing statistical decoding method

Abstract

This invention relates to an iteration sort statistic decode method for low density odd-even check codes (LDPC), in the process of decoding, a sort statistic decoding method is applied to assist the iteration decode based on the amplitude of the accumulation value of the likelihood ratio output in iteration each time by all variable nodes, namely, the variable nodes output and accumulate the likelihood ratios and the absolute value of the accumulated likelihood ratio is defined as the stability of the current iterated nodes then to sort the columns of the nodes and the check matrixes for ascending order based on the stability and carrying out gauss elimination to the sorted matrixes to generate a matrix combining the system after the gauss eliminatioin and code the sorted two stabilized node information sequences to get a set of code words for selection, if there is no final output for the iteration decode, then the code words for selection with the smallest Euclidean distance are selected and received as the decode output.

Description

technical field [0001] The invention relates to a soft-judgment decoding method of a low-density parity check code, and belongs to the technical field of channel error correction coding decoding. Background technique [0002] Among the decoding methods of LDPC codes, the iterative soft-decision decoding method based on bipartite graph, that is, BP decoding, has a good bit error rate performance. For longer irregular LDPC codes, it can achieve performance close to the Shannon limit. However, in practical applications, the system often uses code blocks of short and medium lengths, and the bipartite graph corresponding to the finite-length LDPC code no longer has asymptotically acyclic characteristics, so in this case, BP decoding still has a comparative advantage compared with MLD decoding. big gap. The OSD decoding method is also a kind of soft-decision decoding that was applied to linear block codes earlier, and is suitable for short codes with a certain algebraic structure...

AI Technical Summary

Problems solved by technology

Since the complexity of the OSD decoding method is proportional to N 2 , OSD decoding is performed on the output soft information of each iteration, which will add a lot of delay to each iteration and destroy the high-speed decoding characteristics of LDPC codes

If OSD decoding is started in a certain iteration in the middle of BP decoding, the performance gain obtained by OSD decoding is very small due to the oscillation phenomenon in the soft information output by the current iteration.

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