ANALYSIS OF FINITE-LENGTH ACOUSTIC ECHO CANCELLATION SYSTEM

The acoustic echo canceler using an adaptive transversal filter and the least mean-square (LMS) algorithm is the most effective technique to reduce acoustic echoes in a hands-free telephone system. However, the requirement of a very high order filter for each microphone results in difficulties in convergence and hardware implementation. In this paper, the performance of the finite length adaptive filter is studied. A formula which relates the echo cancellation to the filter size, N, is established. Detailed analysis shows that this finite filter length will have better performance using speech than white noise.