EXIT图分析多进制LDPC码

EXIT charts for nonbinary LDPC codes

多进制LDPC码是二进制LDPC码在有限域GF(q=2p)上的扩展,研究表明在相同帧长和码率下,多进制LDPC码相比二进制LDPC码具有更优异的性能。介绍了EXIT图的基本原理,分析了AWGN信道下多进制LDPC码的迭代收敛性,同时确定其门限值,为后续采用EXIT分析设计实际通信系统奠定理论基础。仿真结果表明,在同样的信通情况下,四进制规则的LDPC码的性能要优于二进制规则的LDPC码,同时也验证了EXIT图工具分析研究迭代性问题的优越性。

Non-binary low-density parity-check （LDPC） codes defined over the finite field GF（ q = 2^p） are an extension of binary LDPC codes and have demonstrated improved performance over binary LDPC codes with the same fiame length and rate. This paper introduces the principle of extrinsic information transfer （EXIT） charts, analyzes the convergence behavior of non-binary LDPC codes on AWGN channel, and confirms the thresholds of non-binary LDPC codes, which provides the foundation for analysis and design of real communication system using EXIT tool in future work. Simulation result shows that the performance of quaternary LDPC codes is better than that of binary LDPC codes in the same channel, and validates the superiority of using EXIT chart for iterative research.