一种新的用于立体声回波对消的基于频移的非线性预处理方法

A New Nonlinear Preprocessing Solution Based on Frequency-shifting to Stereophonic Acoustic Echo Cancellation

针对立体声回波对消中左右两声道的回波具有强相关性而导致自适应滤波器解不唯一、失配大等一系列问题,提出一种新的基于频移变换的去相关非线性预处理方法。在实际立体声回波对消系统中采取将两声道信号交替在时间轴上压缩或拉伸的办法来降低两声道信号的相关性和保证它们时间上的一致性、连续性及实时性,还改进了解相关的DLMS算法。实验显示,在同样听觉效果前提下移频法比已有几种非线性预处理方法的去相关效果好,用真实语音和真实房间冲击响应进行的立体声回波对消仿真实验表明失配和对消性能改善明显。

There are some problems such as no unique solution, large misalignment in stereophonic acoustic echo cancellation（SAEC） caused by high correlation between stereo signals. In this paper, a new nonlinear preprocessing solution based on frequency-shifting to reduce the correlation between the stereo signals was proposed. Two stereo signals are stretched and compressed alternately to keep them synchronism, continuous and real-time. The DLMS algorithm was improved. Experiments showed that compared with the several nonlinear preprocessing means the frequency-shifting solution appear to be the best choice for decreasing the correlation between the stereo signals. Simulation also showed that the solution has better performance when it is applied to stereo acoustic echo cancellation.