QC-LDPC码构造及其在BICM-ID系统中的应用

摘要

基于有限域的两个子集,构造准循环LDPC(Quasi-Cyclic LDPC,QC-LDPC)码的基矩阵,并针对传统算法构造掩模(masking)矩阵的缺陷,设计了一种简单有效的掩模矩阵构造方法.然后,将构造的QC-LDPC码与比特交织迭代译码编码调制(Bit-Interleaved Coded Modulation with Interleaved Decoding,BICM-ID)系统相结合,分别选用QPSK、16QAM、64QAM三种调制方式,对其在高斯白噪声信道和瑞利衰落信道下的性能进行仿真.仿真结果表明:所提方案的误码率性能相对于传统方法有明显改善.%Based on the two subsets of the finite field, the base matrix of the quasi-cyclic LDPC (Quasi-Cyclic LDPC, QC-LDPC) code is constructed. In view of the defects for traditional algorithm, a simple and effective method for constructing the masking matrix is designed. Then, the constructed QC-LDPC code is combined with the Bit-Interleaved Coded Modulation with Interleaved Decoding system, the three modulation modes of QPSK, 16QAM and 64QAM respectively selected, and their performance in Gauss white noise channel and Rayleigh fading channel simulated. The simulation results indicate that there is a significant improvement in the bit-error-rate performance of the proposed scheme compared with the traditional method.