Joint Source-Channel En/Decoding Based on a New Symbol-Level Joint Trellis  

作　　者：TU Guofang LIU Jianjun ZHANG Can WANG Qiang 

机构地区：[1]School of Information Science and Engineering, Graduate University of Chinese Academy of Sciences, Beijing 100049, China [2]State Key Laboratory of Information Security, Graduate University of Chinese Academy of Sciences, Beijing 100049, China

出　　处：《Chinese Journal of Electronics》2011年第1期114-120,共7页电子学报（英文版）

基　　金：This work is supported by the National Natural Science Foundation of China （No.61032006, No.60773137, No.60972067）, Award Foundation of Chinese Academy of Sciences （No.2069901）.

摘　　要：A joint source-channel en/decoding scheme based on a new symbol -level joint trellis for the Variable length coding （VLC） is presented. In the encoder part, the serial VLC and a Recursive systematic convolutional （RSC） code are treated as a single component code, which is parallel with another RSC code through a quantizer. According to the joint source-channel en/decoding model, we construct a new symbol-level joint trellis with compound states by merging a VLC trellis with a eonvolutional trellis. Based on this joint trellis, the symbol-level a posteriori probability （APP） decoding algorithm is also derived, which leads to a joint iterative decoding approach with symbol-level soft outputs. The experimental results show that the joint source-channel en/ decoding scheme has obtained better performance than existent joint iterative decoding based on the bit-level super trellis. As a result, the proposed scheme obtains 0.70 dB gains after the 8-th iteration at an SER of 10-4 and it provides substantial error protection for variable-length encoded image data.

关 键 词：Joint source-channel decoding Variable length coding Turbo codes Iterative decoding Residual source redundancy 

分 类 号：TP301.6[自动化与计算机技术—计算机系统结构] TN911.22[自动化与计算机技术—计算机科学与技术]