Bit- and Trellis- Based Joint Huffman and Convolutional Sequential Decoding Algorithms

• Main Authors: Wei-I Wu, 吳威怡
• Other Authors: Yuh-Ming Huang
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/05464860396541934297

碩士 === 國立暨南國際大學 === 資訊工程學系 === 96 === According to the Shannon’s separation theory, the performance of the overall system is optimal while the source coding and the channel coding are separately optimized. However, due to the constraints on complexity and delay, the performance of separate decoding is usually not optimal. In the past, in order to further improve the performance of separate decoding, the residual redundancy left after compression, the source priori information, and the channel statictical information are exploited and fully utilized for presenting a so-called joint source-channel decoding (JSCD) scheme. In tradition, the trellis adopted in Viterbi decoding algorithm will become tremendously large while all the source and channel information are utilized. Although the decoding performance is optimal, the decoding complexity becomes quite expensive. Therefore, it is not practical. In this work, a new maximum a posteriori probability (MAP) metric with lower computational complexity is derived first, and then we propose a bit- and trellis- based jointly sequential decoding algorithm along with a suboptimal solution. Simulation results indicate the suboptimal method can provide nearly the same performance as optimal scheme while exhibiting a significantly lower complexity.