回声消除基于NLMS改进算法的研究

为了提高VoIP的通信质量，减少回声干扰，对LMS算法、NLMS算法进行阐述，基于NLMS提出了一种运算量小并且提高收敛性能的改进的自适应滤波算法。通过在Matlab下的仿真研究和对误差曲线的分析，证明了该改进算法的收敛速度快，均方误差小。用改进的算法对语音回声信号进行消除，仿真得到消除回声后的信号效果明显，为IP电话中回声消除的自适应滤波问题提供了一个较好的算法。

Study on echo cancellation based on NLMS improved algorithm

In order to improve the communication quality of the voice over Internet protocol（VOIP）and reduce echo inter-ference,an improved NLMS algorithm which has a small amount of computation and can improve convergence performance is proposed based on the analysis of LMS algorithm and NLMS algorithm. By the simulation of Matlab and analysis of the error curve,it is proved the improved algorithm has rapid convergence speed and small mean square error. Through eliminating voice echo signal by means of the improved algorithm,the effect of getting rid of the echo signal obtained by simulation is obvious. A better algorithm was provided for adaptive filtering of canceling the echo in IP phone.