改进Min-sum的LDPC译码算法研究

Research on LDPC Decoding Based on Modified Min-sum Algorithm

为了弥补Min-Sum译码算法相对于LLR-BP算法的性能缺陷,降低LLR-BP算法的实现复杂度,提出一种改进型Min-Sum译码算法,将Normalized BP-Based和Offset BP-Based 2种算法有效地结合,在计算校验节点消息时,同时引进校正因子和偏移因子,并通过最小均方差准则来选择参数。仿真结果表明,在误码率相同的条件下,改进型Min-Sum译码算法比Min-Sum算法、Normalized BP-Based算法和Offset BP-Based算法具有更好的译码性能,译码性能逼近于LLR-BP译码算法。

In order to make up for the performance defects of Min-sum decoding algorithm relative to LLR BP decoding algorithm and reduce implementation complexity of LLR-BP algorithm, a modified Min-sum decoding algorithm is proposed. When the check nodes process the message, parameters of the proposed algorithm are confirmed according to minimum mean square error rule, and the normalized BP-based decoding algorithm and the offset BP-based decoding algorithm are integrated effectively. At the same time, we introduce the correction factor and the offset factor into this algorithm reasonably. The simulation results show that decoding performance of modified Min-sum decoding algorithm is more effective than that of Min-sum decoding algorithm, normalized BP-based decoding algorithm and offset BP-based decoding algorithm under the same condition of bit error rate, and it approaches to the performance of LLR-BP decoding algorithm.