正比例扩展相关LMS 算法

传统的回声消除系统无法在嘈杂的双工环境下工作。由于双工信号的干扰，误差信号
不能正确地指导滤波器系数的更新。本文中提出了一种基于相关函数的自适应滤波算法，扩展型相关函数LMS（ECLMS）算法。计算机仿真结果显示ECLMS 算法的表现要优于传统LMS 算法。然而，ECLMS 的收敛速度仍然不能令人满意。为了提高ECLMS 算法的收敛速度，本文推出了一种新的正比例步长调整算法，针对自适应滤波器系数的每一个抽头，提供一个合理的步长调整参数。计算机仿真结果证实了正比例扩展相关LMS 算法理论的正确性。
关键词：回声消除，自适应滤波器，双工环境，相关函数，正比例步长调整算法
Proportionate Extended Correlation LMS Algorithm CHEN Rui1，E Zhi-feng1，YU Shao-jun1, Mohammad Reza Alsharif2 (1.Central South University of Forestry & Technology, Changsha, China,410004 2.University of the Ryukyus, Okinawa, JAPAN) Abstract: The conventional algorithms in the echo canceling system have drawback when they are faced with double-talk condition in noisy environment. Since the double-talk and noise signal are exist, then the error signal is contaminated to estimate the gradient correctly. In this paper, a new class of adaptive algorithm based on the correlation function processing is presented，which is called Extended Correlation LMS (ECLMS) algorithm. The computer simulation results show that
the ECLMS algorithm has better performance than conventional LMS algorithm. However the
convergence speed is not sufficient. In order to improve the convergence speed, we proposed a new proportionate step-size adjustment algorithm. The computer simulation results support the theoretical findings.
Key words: Echo canceling, LMS algorithm, Double-talk, Correlation function, Proportionate
step-size adjustment algorithm