GB20600标准的LDPC码的改进

尽管LDPC码已经被GB20600标准采纳作为信道编码，与其它LDPC码相比，在同样码长和码率的情况下，GB20600 LDPC码误码率性能并非最佳；GB20600标准的LDPC码的码长达7493，存在编码复杂性问题，但是GB20600 LDPC码未采用基于校验矩阵的快速算法，这给GB20600 LDPC编解码器的硬件实现带来较大的困难。本文在现有GB20600 LDPC码的设计框架下，对GB20600中LDPC码的校验矩阵进行了修改，在此基础上提出一种有效的LDPC码的快速迭代算法，使编解码器的硬件易于实现。改进后的LDPC码的编码算法具有较低的实现复杂度。仿真结果表明，改进后的LDPC码的误包率性能优于现GB20600中LDPC码的误包率性能。 

Improvement of LDPC Codes in GB20600

Though the LDPC code is absorbed into GB20600 standard as a channel coding．the BER performance of GB20600 LDPC code is not very good under the condition of the same code length and code rate comparing with other LDPC codes．The GB20600 LDPC code has a code length of 7493，the encoding complexity problem exists in the encoder implementation，the presented GB20600 has also not considered the fast encoding algorithms. which makes it difficult for GB20600 LDPC codec hardware implementation．Under the frame of the GB20600 LDPC codes，the parity check matrix is revised，which makes it possible to develop a fast iterative algorithm of LDPC codes in the paper．The proposed encoding algorithm and scheme simplify GB20600 LDPC encoder hardware．The encoding complexity of the improved LDPC codes is much lower than that of the existing GB20600 LDPC codes．The simulation results show that the PER(Packet Error Rate)performance of the proposed LDPC codes also is much better than that of existing GB20600 LDPC.