16QAM因其高频谱利用率而被第三代移动通信增强型技术HSDPA采用。由于Turbo译码需要软信息输入，因此，解调输出需要计算比特软信息（LLR）。本文分析了LLR理论算法并在此基础上导出了简化算法。-16QAM its high spectral efficiency have been enhanced third-generation mobile communication technology HSDPA use. Turbo decoding requires soft inform

BPSK,QPSK,16QAM,64QAM调制，以及软比特提取，软比特信息输入译码器，进行软判决译码。-BPSK, QPSK, 16QAM, 64QAM modulation and soft bit extracting, soft bit information input to the decoder and conduct soft-decision decoding.

卷积编码，QAM解调器的软比特信息输入viterbi译码器进行软判决译码。-Convolution coding, the soft bit information QAM demodulator input viterbi decoder and soft decision decoding.