快衰落Rayleigh信道下短LDPC码两类BP-Based译码的优化设计

Optimization of Two BP-Based Decoding Algorithms for Short LDPC Codes on Fast Rayleigh Fading Channel

该文基于最小均方误差(MMSE)准则,对快衰落瑞利(Rayleigh)信道下短码长低密度校验(LDPC)码的ScaledBP-Based和OffsetBP-Based两类改进译码算法进行了优化设计。利用该准则,得出了两类改进算法的最优校正因子,并给出了相应的数值计算。对码长为504和1008的1/2码率(3,6)规则LDPC码实验仿真显示,使用该准则设计的两类算法能够取得优于置信传播(BP)算法的译码性能。

By using the Minimum Mean Square Error （MMSE） criterion, the design of two improved Belief Propagation （BP）-based, i.e., the scaled BP-based and offset BP-based algorithms is presented, for decoding of short Low-Density Parity-Check （LDPC） codes on the fast Rayleigh fading channel. Based on the MMSE criterion theoretical formulas and numerical calculations on the optimum factors for these two BP-based algorithms are provided. The simulation results for the （3,6） regular LDPC codes of lengths 504 and 1008 on the fast Rayleigh fading channel demonstrate that the scaled BP-based and offset BP-based algorithms with the proposed factors can achieve the performance better than that of the BP algorithm.