一种利用软判决的信道编码识别新算法

摘要

The existing methods for channel coding recognition usually use hard-decision of the demodulator output sequence, and their robustness against error bits is to be improved.Focusing on situations of low signal-to-noise ratio, this paper presents a novel recognition algorithm which uses soft-decision.The algorithm is based on the error-containing equation model, and it solves the equation, thus accomplishes the recognition, through regarding the probability that the equation holds right as the measurement of the performance of a solution vector. The use of log-likelihood ratio(LLR) algebra makes the algorithm greatly simplified. Results of simulation experiments show that the new algorithm improves recognition performance,especially in lower signal-to-noise ratio cases,compared to the existing algorithm based on Walsh-Hadamard transform.%现有的信道编码识别方法通常利用解调输出的硬判决序列来进行,其容错能力有待提高.本文针对低信噪比的接收信号,提出了一种利用软判决的编码识别新算法.该算法基于含错方程模型,以方程成立的概率作为衡量解向量性能的量度,从而求解方程,完成识别.对数似然比(LLR)代数的使用使得算法具有简单的形式.仿真实验表明,与基于Walsh-Hadamard变换的传统算法相比,新算法提高了识别性能,且信噪比越低,性能提高越显著.