Construction of LDPC Codes Based on Circulant Permutation Matrices: Construction of LDPC Codes Based on Circulant Permutation Matrices

Quasi Cyclic LDPC (QC-LDPC) codes are of particular interest in various areas. In this paper, a method to construct a class of QC-LDPC codes based on circulant permutation matrices is showed. The method chooses the position of each non-zero sub-matrix in the bipartite graph based on blocks. Then the circulant permutation value of each sub-matrix is decided. With the proposed algorithm, a few LDPC codes were constructed with the code length from 1008 bit to 8064 bit and with code rate from 1/2 to 7/8. Simulation results show that the proposed LDPC codes are superior to QC-LDPC codes with other construction algorithms.