基于QC-LDPC码的联合信源信道编码研究

基于欧式几何构造的准循环LDPC码(quasi-cyclic LDPC,QC-LDPC)应用于联合信源信道编码(joint source and channel coding,JSCC)系统中,由于JSCC系统中信源码和信道码存在特殊的边连接关系,致使满足信源码字和信道码字之间特殊连接关系的QC-LDPC码字比较少,但至少QC-LDPC码可以用来作为JSCC系统中的信道码.仿真结果表明,双QC-LDPC码的JSCC系统纠错性能相比双随机LDPC码的JSCC系统有明显的改善,同时前者的译码迭代次数明显少于后者,从而提升了译码效率.仅使用QC-LDPC码作为信道码的JSCC系统也比双随机LDPC码的JSCC系统有更好的性能,且其迭代次数也更少.

Research on joint source and channel coding based on QC-LDPC code

In this paper, quasi cyclic low density parity check (QC-LDPC) codes based on Euclidean geometry are applied into the JSCC system. Since there are special links between the source code and the channel code in the JSCC system, it is difficult to construct two QC-LDPC codes which can be applied into the JSCC system. However, at least we can use a QC-LDPC code as the channel code in the JSCC system. Simulation results show that the performance of the JSCC system based on double QC-LDPC codes is significantly improved compared to that of the JSCC system based on the double random LDPC code, and the decoding iteration number of the former is obviously less than that of the latter, and thus improves the decoding effectively. The JSCC system just only using QC-LDPC code as the channel code performs better than that based on double random LDPC codes, and it also requires less iteration.