LDPC码改进高速译码算法

Modified High-speed LDPC Decoding Algorithm

Shannon的学生Gallager首次提出LDPC码的概念和完整的译码方法,目前LDPC码正向着高速高增益的方向发展。针对高速LDPC码译码技术的迫切需求,利用传统最小和算法译码过程中信息迭代的特征,对最小和算法进行简化,使得译码模块能够完成更高并行度的译码工作,同时不造成译码器误码性能的过大损失。使用改进算法实现的高速译码模块,水平运算时间缩短为传统算法的一半,总的译码吞吐量提高50%,在120MHz时钟、10次迭代的情况下,CCSDS近地通信码的译码速度能够达到657.53Mb/s。

Gallager, the student of Shannon proposed the concept and a whole set of decoding method of LDPC code. The LD- PC code speed is higher and higher, and the performance is better and better. Aiming at the exigent demand of high speed LDPC decoder, using the feature of information iteration during the traditional min-sum algorithm, the min-sum algorithm is simplified, and its parallel degree is higher without outstanding loss of BER performance. The calculation time of CNU based on this algorithm is half of the one of traditional algorithm and the throughput increases 50%. When the cloek frequency is 120MHz and the iteration number is 10, the decoder based on the proposed simplified min-sum algorithm has the decoding speed of 657.53Mb/s for the near earth code of CCSDS.