并行级联Gallager码的动态最大外迭代次数译码方案的研究

PCGC(Parallel Concatenated Gallager Code,并行级联Gallager码)是将LDPC(Low Density Parity Check,低密度奇偶校验)码运用于并行级联编码形式而得到的一种新型编码,它的译码器采用双层迭代的形式.传统的PCGC译码器采用FMSIN(Fixed Maximum Super Iteration Number,固定最大外迭代次数)的方案,在信道SNR(Signal-to-Noise Ratio,信噪比)较低时会导致译码器平均迭代次数,也即译码器复杂度偏高.针对于此,本文提出一种根据信道信噪比状况动态调整译码器中最大外迭代次数的方案,并通过计算机仿真,验证了运用此方案后,译码器复杂度可得到较大程度的降低.

Study on dynamic maximum super iterative number scheme in decoder of Parallel Concatenated Gallager Code

PCGC ( Parallel Concatenated Gallager Code) is a new class of channel code who concatenate LDPC (Low Density Parity Check) code in parallel, and it is decoded in two layer iterative style. In general, the MSIN (Maximum Super Iteration Number) of PCGC decoder is fixed, which directs the average iteration number of decoder to be large when the channel SNR (Signal-to-Noise Ratio) is low. To resolve this problem, we present a scheme which dynamically adjusts maximum iterative number according to the channel SNR. The computer simulation results prove that the scheme can reduce the complexity of PCGC decoder efficiently.