Improved syndrome-based ordered statistic decoding algorithm for LDPC codes

Ordered statistics decoding (OSD) algorithm and syndrome–based decoding algorithm are investigated in this work, based on which, a syndrome-based ordered statistics decoding (SOSD) algorithm for LDPC codes is proposed. The indexed systematic form of parity check matrix is obtained based on the least reliable independent positions (LRIPs) by performing Gaussian eliminations, which promises that the SOSD processing need not the re-encoding process, but only several binary vector additions, therefore achieves noticeable computation complexity reduction.