非规则全分集LDPC码的构造方法

提出一种基于渐进边增长（Progressive Edge．Growth，PEG）算法的非规则全分集低密度奇偶校验（Low—Density Parity—Check，LDPC）码的构造方法。首先根据度分布和码率，对非规则全分集LDPC码中的节点进行度分配；然后对PEG算法中校验节点的选择标准加以约束，生成消除短环的非规则全分集LDPC码；进一步，通过改变局部校验节点剩余度的方法，解决在特殊度分布下算法失效的问题。仿真结果表明，构造的非规则全分集LDPC码在瑞利块衰落信道下能够实现全分集；在码长、码率相同的情况下与规则全分集LDPC码相比，非规则全分集LD—PC码能够获得更高的编码增益。

Construction method for irregular full diversity LDPC codes

A progressive edge-growth （PEG） based algorithm is proposed to construct irregular Iulldiversity low-diversity parity-check （LDPC） codes. First, according to degree distribution polynomialsand the code rate, all nodes are allocated with different degrees. Second, the criteria of selecting checknodes in the PEG algorithm is performed in a restricted way without containing short eyeles. In addition,the failures of PEG algorithm in some special cases are conquered by modifying the residual degree ofsome check nodes, the simulation results show that the irregular full diversity LDPC codes constructedwith the proposed algorithm can obtain full diversity over block fading channel. Meanwhile, the irregularLDPC codes are shown to outperform the regular ones with the same code length and code rate.