改进的变步长LMS自适应滤波算法分析  

Performance Analysis of an Improved Variable Step Size LMS Algorithm

作　　者：刘明园[1,2] 徐松涛[1] 刘凯[1] 甘元[1] 

机构地区：[1]空军工程大学工程学院 [2]解放军69018部队

出　　处：《火力与指挥控制》2010年第12期110-112,118,共4页Fire Control & Command Control

摘　　要：通过建立步长因子μ与误差信号e(n)之间的非线性函数关系,提出了一种改进的自适应变步长最小均方(LM S)算法。该算法克服了LM S算法在自适应稳态阶段μ取值偏大的缺陷,具有在误差e(n)接近零处缓慢变化的特点。该算法还具有初始阶段和未知系统时变阶段步长自动增大而稳态时步长很小的特点,解决了收敛时间和稳态误差的矛盾。将该算法对比一般的变步长算法,该改进算法在平稳过程中具有更小的稳态误差,同时还具有更好的跟踪时变系统的能力。By building a nonlinear function relationship between the step size μ（n） and the error signal e（n）,this paper proposes an improved variable step size LMS（Least Mean Square） adaptive filtering algorithm.This variable step size algorithm avoids the shortcoming of changing step size of SVSLMS（variable step size LMS based on Sigmoid function）.Also in the stage of adaptive steady state it has the virtue of e（n） slightly changing at point close to zero.Meanwhile the algorithm efficiently overcome the discrepancy between the convergence rate and the steady error.This algorithm constitutes a significant improvement in the identificated speed with very small steady error in stationary environment and is of better tracking capability,as compared with the traditional algorithms with step size.

关 键 词：最小均方算法 变步长 自适应滤波 

分 类 号：TN911.7[电子电信—通信与信息系统]