迭代更新信源模型参数的信源-信道联合译码  

Joint Source-Channel Decoding Based on Iterative Source Model Parameter Update

作　　者：殷玮玮[1] 吴乐南[1] 

机构地区：[1]东南大学无线电工程系,江苏南京210096

出　　处：《应用科学学报》2006年第4期345-348,共4页Journal of Applied Sciences

基　　金：国家自然科学基金资助项目(60072013)

摘　　要：提出一种在HMM基础上同时更新模型参数和译码的信源信道联合译码算法.通过接收到的含噪声信息序列以及由训练序列获得的先验知识对信源模型参数重新估计,将参数更新与联合译码过程迭代进行,一方面得到了信源序列更精确的概率结构,另一方面提高了联合译码的性能,并从信息论角度给出了信源模型参数的改善量.A joint source-channel decoding scheme implemented by simultaneously decoding and updating parameters based on HMM is proposed. First, the source parameter used in the joint source-hannel decoding is updated by the α pr/or/ knowledge obtained through the training sequence and the received noisy information sequence. The joint sourcechannel decoding is then employed. These two steps are implemented iteratively. The iterative updating algorithm improves precision of the probability structure of the received sequence and performance of the joint source channel decoding. The degree of parameter improvement of the source model can be obtained from the perspective of the information theory.

关 键 词：信源信道联合编译码 隐马尔可夫模型 迭代 Baum-Welch算法 鉴别信息 

分 类 号：TN91[电子电信—通信与信息系统]