中国数字地面电视标准中LDPC码的半并行译码结构设计

Design of decoder for LDPC codes used in CDTTB standard

中国数字地面电视广播标准采用准循环低密度校验码(QC-LDPC)作为其信道编码的内码。根据该类LDPC码的准循环特性,提出了一种基于后验概率的简化最小和算法及其对应的半并行译码结构。其可实现在同一接收机中尽量复用硬件资源并减少消耗情况下LDPC码的多码率译码。最后,使用可编程门阵列实现了此结构并验证了其性能,实验表明,该方法比传统的最小和算法性能略有降低,但可节约大量存储器资源。

Quasi-cyclic low-density parity-check codes （QC-LDPC） have been adopted as the inner code of channel codes in Chinese digital terrestrial television broadcasting standard （CDTTB）. Based on its systematic circulant form, this paper presented a simplified rain-sum decoding algorithm based on aposteriori probabilities and its corresponding decoder with semi-parallel architecture. The decoding of LDPC codes at multiple rates can be achieved in one receiver. With fully multiplexing the hardware resources are reduced on the premises that the payload rates are met. The properties of the decoder are verified on FPGA.