A new modified UMP BP decoding algorithm of quasi-cyclic LDPC codes based on oscillation estimation

A modified algorithm based on the Uniformly Most Powerful Belief Propagation (UMP BP) algorithm are studied for decoding implementation of regular QC-LDPC codes by introducing two factors of mean square difference and ratio in check processing. The decoding algorithm is a combination of soft decision and hard decision to adaptively decrease the oscillation caused by the change of ex-LLRs sign, further to reduce the errors of UMP BP algorithm caused in first iteration, Simulation result shows that implementation of improved DARBFMS algorithm outperform conventional algorithms. Compared with the improved algorithm in irregular LDPC codes, performance in QC-LDPC codes seems better.