• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.1
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• pp.117-124
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• 2012

In this paper, we propose a simple H parity check matrix from the CPM(circulant permutation matrix), which can easily avoid the cycle-4, and approach to flexible code rates and lengths. As a result, the operations of the submatrices will become the multiplications between several CPMs, the calculations of the LDPC(low density parity check) encoding could be simplest. Also we consider the fast encoding problem for LDPC codes. The proposed constructions could lead to fast encoding based on the simplest matrices operations for both regular and irregular LDPC codes.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.11
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• pp.36-42
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• 2010

This paper presents a hybrid approach to the construction of quasi-cyclic (QC) low-density parity-check (LDPC) codes based on parallel bundles in Euclidean geometries and circulant permutation matrices. Codes constructed by this method are shown to be regular with large girth and low density. Simulation results show that these codes perform very well with iterative decoding and achieve reasonably large coding gains over uncoded system.