LT码的BPML译码算法  

BPML Decoding Algorithm of LT Codes

作　　者：朱宏鹏[1] 李广侠[1] 冯少栋[1] 

机构地区：[1]解放军理工大学通信工程学院,南京210007

出　　处：《计算机科学》2009年第10期77-81,共5页Computer Science

摘　　要：采用置信度传播算法(BP)对LT码进行译码时,停止集是影响译码效率的重要因素。对LT码停止集的大小进行了理论分析和仿真,提出了置信度传播-最大似然联合译码算法(BPML)。该算法首先采用BP算法译码,当遇到停止集时再采用最大似然译码算法(ML)对停止集进行处理,能够有效消除停止集的影响,提高LT码的译码效率。仿真结果表明,BPML算法结合了BP算法复杂度低和ML算法译码效率高的优点。研究结果对提高计算机网络中数据分发应用的分发效率具有重要的实用价值。For Belief Propagation（BP） decoding algorithm of LT codes, stopping set prohibits the improvement of decoding efficiency. This paper analyzed and simulated the size of stopping set. A Belief Propagation-Maximum Likelihood decoding algorithm（BPML） was proposed. BPML uses BP algorithm to decode firstly. When stopping set makes BP stop, Maximum Likelihood（ML） decoding algorithm is used to deal with the stopping set. It can overcome the negative influence of stopping set and improve the decoding efficiency of LT codes. The simulation showed that BPML combines the advantages of BP algorithm in low decoding complexity and ML algorithm in high decoding efficiency. The conclusion of research is practically valuable in improving efficiencies of data distribution applications in computer networks.

关 键 词：数据分发 喷泉码 LT码 BPML 停止集 

分 类 号：TN911.22[电子电信—通信与信息系统]