一种改进变步长LMS算法的性能研究

A New Variable Step Size LMS Adaptive Filtering Algorithm and Its Analysis

在对传统LMS算法、变步长LMS算法及其改进算法分析的基础上,提出了一种改进的变步长LMS算法。新算法通过建立步长因子与误差信号之间的非线性函数关系,使其初始阶段和时变阶段步长自适应增大和稳态阶段步长很小,理论分析及计算机的仿真结果表明,该算法可保证较快的收敛速度和较小的失调,能更好地解决收敛速度和稳态误差的内在矛盾,可更好地应用于自适应系统中。

Based on a brief analysis of traditional LMS, variable step size LMS algorithm and its improved algorithm, a modified LMS algorithm of variable step size is proposed. The novel algorithm based on nonlinear functional relationship between the step-size and the error, increases adaptively at the beginning of the algorithm or when the channel is varying with time, and it would be smaller during the steady state. So the algorithm has the excellences of faster constringency, little steady error, tracking the change of the system and avoiding the effects of the noise. The theoretical analysis and computer simulation prove that the algorithm is better than traditional LMS algorithm.