Design of online echo canceller in duplex mode

Abstract

A new online echo canceller system was developed that perfectly works in the duplex mode and shows a good performance in the conventional half-duplex mode. The near speech signal is not corrupted in the duplex mode by the linear compensation procedures but degrades significantly by nonlinear suppression. The conventional linear compensation system is based on the LMS adaptation or its modifications that do not provide a necessary high accuracy of a big number of the impulse response coefficients. We have implemented the LS method for online estimation of the full impulse response using the superfast Schur algorithm for Toeplitz matrix inversion. Implementation details are important. They include numerical accuracy, initialization, update criteria, packet control. Good results of an echo compensation are shown on the data from the Matlab Audio System Toolbox.