基于后验概率的低密度奇偶校验码逆向识别方法研究  

Research on Low Density Parity Check Code Reverse Recognition Methods Based on Posterior Probability

作　　者：刘婉月[1] 包昕[1] 王达[1] 金野[1] 

机构地区：[1]北京大学信息科学技术学院,卫星与无线通信实验室,北京100871

出　　处：《北京大学学报（自然科学版）》2016年第3期389-395,共7页Acta Scientiarum Naturalium Universitatis Pekinensis

摘　　要：提出一种基于后验概率对数似然比(LLR)均值的逆向识别低密度奇偶校验码(LDPC)校验矩阵的方法。通过估计接收码字的信道增益以及信道噪声方差值,得到后验概率对数似然比,并依据后验概率对数似然比均值最大化原则,成功实现对LDPC码校验矩阵的逆向识别。仿真结果表明,在加性高斯白噪声信道条件下,利用所提出的LDPC码逆向识别技术,接收方可准确无误地找到发送方使用的LDPC码校验矩阵。This paper presents a method of the reverse recognition of the check matrix coded by low density parity check code（LDPC）, which is based on the posterior probability log likelihood ration（LLR）. The posterior probability LLR was obtained by estimating the channel amplification and the variance of the noise in the received code. A reverse recognition of LDPC code check matrix was achieved following the LLR mean value maximization principle. Simulation results show that the receiver can precisely retrieve the LDPC check code used by the sender under different channel circumstances through the LDPC reverse recognition method.

关 键 词：低密度奇偶校验码(LDPC) 逆向识别 后验概率对数似然比(LLR) 

分 类 号：TN911.22[电子电信—通信与信息系统]