快速生成QAM比特置信度软判决度量的算法

在现代通信系统中，为了保证高的信道解码增益，信道解码器均采用软输入技术。传统的软判决度量大多是基于最小欧氏距离准则生成，该文提出一种基于比特置信度快速生成QAM软判决度量的算法，通过将比特置信度引入到QAM软判决度量的计算中来减少计算的复杂性。相比基于最小欧氏距离的软判决度量生成算法，该文提出的方法在保证信道解码器性能的前提下，减少了生成软判决度量的运算量。应用于中国数字电视地面传输标准DTMB系统的仿真结果表明，该文提出的软判决度量生成算法虽然降低了计算量，但性能几乎没有任何损失，具有良好的性能和可实现性。

Bit Confidence-Based Soft Decision Metric Generation for QAM

In modern communication systems, a channel decoder usually employs the soft input to guarantee a high channel decoding gain. A new soft decision metric for QAM is presented in this paper. Unlike traditional soft decision metric based on minimum Euclidean distance, the proposed metric is based on the bit confidences. Compared to traditional soft decision metric, the one presented in this paper can guarantee the channel decoder performance with less computation complexity. The numerical results applying the proposed method to the DTMB system indicate that the proposed soft decision metric reduces the computation complexity without any performance degradation. These results also show that the proposed metric is a good alternative for soft decision generations.