Construction of girth‐eight quasi‐cyclic low‐density parity‐check codes with low encoding complexity
Ruyan Wang, Yong Li, Hui Zhao, Liang Qin, Hong Zhang · IET Communications · 2016
A construction method for girth‐eight quasi‐cyclic low‐density parity‐check codes (QC‐LDPCs) with low encoding complexity is proposed in this study. To avoid short cycles and further improve the performance of the authors proposed codes, the greatest common divisor (GCD)‐based method is utilised to construct the information part with girth‐eight of the parity‐check matrix with systematic form. Furthermore, the quasi‐dual‐diagonal structure is adopted as the parity part of the parity‐check matrix for fast encoding, which not only maintains the parity‐check matrix with girth‐eight, but also efficiently decreases the encoding complexity of their proposed codes. Simulation results show that their proposed codes perform better than Mackay's codes and the QC‐LDPCs constructed by the GCD‐based method, and have comparable performance compared with progressive edge growth based QC‐LDPCs. Besides, their proposed codes have lower encoding complexity due to the property of fast encoding.