Construction Methods of S-QC-LDPC Based on 0-1 Programming Algorithm

This paper analyzes the design of Quasi-Cyclic LDPC (QC-LDPC) without length-4 circle firstly. Because of some limits in structures of QC-LDPC such as other rows or columns will be determined with a given row or column and short circles will appear with a given short circle in the parity check matrix where is the order of sub matrix, we deal with the problems with the proposed similar S-QC-LDPC (S-QC-LDPC) based on 0-1 programming. The main idea is looking for constraint conditions without length-4 circles. Moreover, in designing the S-QC-LDPC, we find its particular matrix reflecting the check matrix similar to circulant permutation matrix of QC-LDPC. The simulation results show the proposed S-QC-LDPC can significantly improve the BER performance compared with QC-LDPC.