Delayed-X LMS algorithm: An efficient ANC algorithm utilizing robustness of cancellation path model

Abstract

In conventional ANC (Active Noise Control), the cancellation path is usually modelled by a FIR filter with many coefficients. In this study, a Delayed-X LMS algorithm is investigated of which the computational load is much less than that of the Filtered-X LMS method for a long duct or narrow band noise cancellation application This algorithm is based on the hypothesis that the cancellation path model for the Filtered-X LMS method does not have to be accurate and can be represented by a delay in such cases. The steady state weight vector solution in the presence of model error is investigated to show the validity of using an erroneous simplification. The ADE (Adaptive Delay Estimation) method is proposed for effective delay estimation of the cancellation path, which can be used with the Delayed-X LMS algorithm on-line or off-line. Simulation and experimental results demonstrate the effectiveness of the Delayed-X LMS algorithm for the specified applications. (C) 1998 Academic Press Limited.