摘要
This paper proposes a modification of the soft output Viterbi decoding algorithm (SOVA) which combines convolution code with Huffman coding. The idea is to extract the bit probability information from the Huffman coding and use it to compute the a priori source information which can be used when the channel environment is bad. The suggested scheme does not require changes on the transmitter side. Compared with separate decoding systems, the gain in signal to noise ratio is about 0 5-1.0 dB with a limi...
提出了一种与Huffman码相结合的卷积码软判决译码方案 .对卷积码的软判决维特比译码算法进行了改进 ,由Huffman编码的码字概率计算出比特转移概率 ,进而得出与维特比译码的支路似然值相对应的信源先验信息 ,通信系统的编码端不作改动 ,当由于信道条件恶化等原因造成维特比译码算法的支路量度相差很小而难以进行可靠译码时 ,将信源先验信息作为支路量度的修正值 ,以改善译码的性能 .与分离的信源、信道译码相比 ,性能增益约为 0 5～ 1.0dB ,增加的复杂性很小 .仿真实验验证了算法的有效性 .
基金
theNationalNaturalScienceFoundationofChina (60 0 72 0 13 )
