深空通信中LDPC码的一种译码算法

A Novel Decoding Algorithm of LDPC Code for Deep Space Communication

LDPC码由于具有逼近仙农极限的性能和硬件可实现的编译码复杂度,在深空通信中具有重要的应用前景。文章在简要介绍CCSDS(空间通信系统咨询委员会)中LDPC码编码规范的基础之上,采用多维EXIT图对其译码门限和收敛速度进行了研究,最后重点研究了译码算法,通过改进归一化最小和算法提出了一种自适应归一化最小和算法,该算法保留了归一化最小和算法的所有优点,改善了不同信噪比条件下的译码性能,并解决了归一化因子的选择难题,适合在资源受限的深空通信中应用。

A LDPC code is very promising in deep space communication due to its near Shannon limit performance and practicable complexity.The LDPC specification of CCSDS（Consultative Committee for Space Data System） is presented briefly at first,and the code performance is analyzed by using multi-dimension EXIT curvy.Then,the decoding algorithms are investigated in depth,and a novel decoding algorithm is proposed based on auto-adaptively adjusting normal factor in normalized MinSum algorithm.The novel algorithm outperforms the latter at different signal noise ratio and is fit for deep space communication due to its better performance and low complexity.