Abstract: Bit-Flopping（BF） algorithm and several Weighted BF（WBF） algorithms are investigated, based on which, a new improved WBF（IWBF） decoding algorithm for LDPC codes is proposed. The error metric in WBF considers the check information. Based on that, the IWBF algorithm further considers the impact of message reliability on the symbol decision, but the weighting parameters must be obtained through simulation to achieve better decoding performance. Considering both the check information and the message reliability, the new IWBF decoding algorithm can achieve better decoding performance, but do not bother to choose the weighting parameters. The simulation results show that the proposed algorithm is effective, and can achieve a good decoding performance.

Key words: LDPC codes, Weighted Bit-Flipping（WBF）, message reliability

摘要： 在研究几种加权比特翻转算法的基础上，提出了一种新的针对LDPC码的改进加权比特翻转算法。加权比特翻转（WBF）算法中的错误度量考虑了校验节点的可信度信息，在此基础上，相关的改进WBF（IWBF）算法考虑了消息本身对符号判决的影响，进一步提高了性能。但是在IWBF算法中，必须通过仿真，才能获得使译码性能较优的符号可信度加权参数。提出了一种同时考虑符号可信度和校验可信度的算法，不需要调整加权参数，即可获得较优性能。仿真显示提出的加权比特翻转算法是可行且有效的。

关键词: LDPC码, 加权比特翻转, 符号可信度