基于稀疏序列LDPC的多层码的迭代译码

Iterative decoding for sparse sequence LDPC-coded multilevel coding

提出一种稀疏二进制序列构造的LDPC码作为分量码,译码采用串行迭代的多层码方案.每次串行迭代译码逐层进行,低层向高层传递译码软信息.采用该方案分别对8PSK和16QAM调制的多层码进行串行迭代译码和并行迭代译码的性能仿真.仿真结果表明:该方案的编码复杂度较低,相比于并行迭代译码,串行迭代译码简化了译码结构,且2种迭代译码算法复杂度相同;在AWGN信道和平坦瑞利衰落信道中,串行迭代译码的误比特性能优于并行迭代译码.

A new MLC （multilevel coding ） scheme with sparse binary sequence constructed LDPC （low-density parity-check codes） as component codes and a serial iterative decoding algorithm is presented. Every level decoder works serially and soft decoding information is passed from lower levels to higher levels. In 8PSK and 16QAM modulated multilevel schemes, error performance of two different iterative decoding algorithms were compared. Simulation results show that this new MLC scheme can achieve low encoding complexity. Compared with parallel iterative decoding, serial iterative decoding simplifies decoder construction. Moreover, on AWGN （added white Gauss noise） channel and flat fading channel, serial iterative decoding algorithm can achieve better error performance than parallel iterative decoding algorithm with same computing complexity.