Integrating Acoustic Echo Cancellation In LPC-based Speech Coders 57 Integrating Acoustic Echo Cancellation In LPC-based Speech Coders

This paper presents a novel acoustic echo canceller (AEC) consisting of an adaptive FIR filter and a double-talk detector. By employing the widely used LPC-based speech coder for decorrelation, we de-velop a variable step-size decorrelation NLMS algo-rithm for the adaptive FIR filter and an echo-path mismatch detection algorithm for the double-talk de-tector. This new approach reduces the computational complexity from O(N2) to O(N) for both algorithms of echo cancellation and doubletalk detection. Simu-lation results show that the proposed algorithms im-prove the performance of both echo cancellation and double-talk detection greatly compared to other al-gorithms. 1