Conjugate Gradient Based Adaptive Algorithm for Nonlinear AEC

Recently, to mitigate the loudspeaker-based distortion in the acoustic system, the functional link adaptive filter – based nonlinear acoustic echo cancellation (NAEC) algorithm has been proposed. However, the usage of sine and cosine functions in nonlinear modeling coupled with the steepest descent based weight adaption limits the echo cancellation performance when the underlying distortion has faster time varying amplitude levels. Hence, in this paper, we propose a conjugate gradient (CG)-based algorithm referred to as nonlinear improved sparse conjugate algorithm. It employs the sine and cosine terms but, with time-varying coefficients to enhance distortion modeling and also an improved CG method in improving the echo cancellation performance of NAEC. The simulation results demonstrate the effectiveness of the proposed algorithm compared to the existing functional link-based NAEC.