傳統的回聲消除系統無法在嘈雜的雙工環境下工作。由于雙工信號的干擾，誤差信號
不能正確地指導濾波器系數的更新。本文中提出了一種基于相關函數的自適應濾波算法，擴展型相關函數LMS（ECLMS）算法。計算機仿真結果顯示ECLMS 算法的表現要優于傳統LMS 算法。然而，ECLMS 的收斂速度仍然不能令人滿意。為了提高ECLMS 算法的收斂速度，本文推出了一種新的正比例步長調整算法，針對自適應濾波器系數的每一個抽頭，提供一個合理的步長調整參數。計算機仿真結果證實了正比例擴展相關LMS 算法理論的正確性。
關鍵詞：回聲消除，自適應濾波器，雙工環境，相關函數，正比例步長調整算法
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