A Variable Step-Size Proportionate NLMS Algorithm for Identification of Sparse Impulse Response

作者:Liu Ligang*; Fukumoto Masahiro; Saiki Sachio; Zhang Shiyong
来源:IEICE Transactions on Fundamentals of Electronics Communications and Computer Sciences, 2010, E93A(1): 233-242.
DOI:10.1587/transfun.E93.A.233

摘要

Recently, proportionate adaptive algorithms have been proposed to speed up convergence in the identification of sparse impulse response. Although they can improve convergence for sparse impulse responses, the steady-state misalignment is limited by the constant step-size parameter. In this article, based on the principle of least perturbation, we first present a derivation of normalized version of proportionate algorithms. Then by taking the disturbance signal into account, we propose a variable step-size proportionate NLMS algorithm to combine the benefits of both variable step-size algorithms and proportionate algorithms. The proposed approach can achieve fast convergence with a large step size when the identification error is large, and then considerably decrease the steady-state misalignment with a small step size after the adaptive filter reaches a certain degree of convergence. Simulation results verify the effectiveness of the proposed approach.