一种新的变步长LMS自适应滤波算法及性能分析

研究了自适应最小均方误差(least mean squares,LMS)滤波算法的步长选取问题。在详细分析现有变步长LMS算法的基础上,给出一种以双曲正切函数的改进形式为变步长的LMS算法。讨论了步长参数的选取原则及其对算法收敛性、抗干扰性和稳态误差的影响。该算法不但具有较快的收敛速度和跟踪速度,而且能获得更小的稳态失调。理论分析和仿真结果表明,该算法具有更好的稳态性能。

New variable step size LMS adaptive filtering algorithm and its performance analysis

The problem of step size selection for adaptive least mean squares(LMS) filtering algorithm is studied.A new variable step size LMS algorithm with improved hyperbolic tangent function is presented,which is derived by the extensive review about some existing LMS algorithms.The selective rule of step size parameters is discussed,and the performance analysis such as convergence,anti-interference and the steady-state error of the algorithm are also given.The algorithm can not only obtain the good properties of the fast convergence and the tracking speed,but also achieve lower misadjustment.Theoretical analysis and simulation results show that the proposed variable step size LMS algorithm has better steady-state performance than that of the existing algorithms.