QC-LDPC码基矩阵构造方法

利用发现的大衍数列和Golomb-Ruler的特殊性质,给出了两种准循环LDPC码的校验矩阵基矩阵的构造方法。根据校验矩阵不含长度为4的环的充要条件判断,设计的两种准循环LDPC码的环长至少为6。仿真显示,在10-5误码率条件下,这两种设计方案比传统的RS码和卷积码级联编码方案有接近2dB的性能提升;相比于IEEE 802.16e标准给出的设计方案,基于Golomb-Ruler构造的QC-LDPC码在性能上有0.8dB的差距,基于大衍数列构造的QC-LDPC码在性能上有0.9dB的差距;基于Golomb-Ruler构造的QC-LDPC码与基于大衍数列构造的QC-LDPC码有几乎接近的性能,前者比后者大约有0.1dB的增益。

Construction methods of basis matrix for QC-LDPC code

By using the special properties of Dayan Sequence and Golomb-Ruler,two methods are proposed to construct basis matrix of parity check matrix for quasi cyclic low density parity check code.According to the necessary and sufficient condition for parity check matrix that has no circle of length four,the designed QC-LDPC codes have circles no less than six.At the BER of 10-5,the simulation shows that comparing with RS and convolution code concatenate methods,the designs have nearly 2 dB more performance improvement.Meanwhile,comparing with methods proposed by IEEE802.16e standard,Golomb-Ruler method has 0.8dB performance decrease and Dayan Sequence method has 0.9dB performance decrease.Those two methods have almost the same performance,the former has 0.1 dB gain than the latter.