基于DTMB标准的新型LDPC译码器实现

Implementation of a new LDPC decoder based on DTMB

针对中国数字电视地面广播标准(DTMB),提出一种新的半并行结构的LDPC译码器.该译码器采用分层消息传递机制,与传统的泛洪传递机制相比,减少了迭代次数,提高了译码器吞吐率;同时,通过切割子矩阵的方法,进一步提高译码器的串行度,降低了译码器硬件资源的占用.最后,译码器采用了一种基于桶形移位器的交叉网络来传递数据,不仅降低了连线复杂度,而且在不改变硬件结构的情况下,可以同时支持DTMB系统三种码率的LDPC译码.

A new semi-parallel LDPC decoder is proposed for DTMB. It is designed based on layered message-passing schedule which improves throughput with less iterations compared with flooding schedule. Besides,it needs less hardware resources by dividing submatrix to improve serial factor of decoder. Lastly,a permute network based on barrel-shifter is adopted to pass message,which not only reduces complexity of interconnection,but also supports three code rates of LDPC codes in DTMB while the decoder architecture needn’t to be changed.