An Acoustic Echo Canceller using Moving Window to Track Energy Variations of Double-Talk-Detector
Subject Areas : Signal Processing
Mouldi MAKDIR
1
*
,
Mohamed BOUAMAR
2
,
Mourad BENZIANE
3
1 - Department of Electronics, Faculty of Technology, University of M’sila, M’sila, 28000, Algeria
2 - Department of Electronics, Faculty of Technology, University of M’sila, M’sila, 28000, Algeria
3 - Laboratory of Analysis of Signals and Systems, M’sila, 28000, Algeria
Keywords:
Abstract :
As a fundamental device in acoustic echo cancellation (AEC) systems, the echo canceller based on adaptive filters relies on the adaptive approximation of the echo-path. However, the adaptive filter must face the risk of divergence during the double-talk periods when the near-end is present. To solve this problem, the double-talk-detector (DTD) is often used to detect the double-talk periods and prevent the echo canceller from being disturbed by the other end of the speaker’s signal. In this paper, we propose a DTD based on a new method that can detect quickly and track accurately double-talk periods. It is based on the sum of energies of the estimated echo and the microphone signals which is continuously compared to the error energy. A window that moves with time and tracks energy variations of the different input signals of the DTD represents a fundamental feature of the proposed method compared to several other methods based on correlation. The goal is to outperform conventional normalized cross-correlation (NCC) methods which are well-known in terms of small steady-state misalignment and stability of decision variable. In this work, the normalized least mean squares (NLMS) algorithm is used to update the filter coefficients along speech signals which are taken from the NOIZEUS database. Efficiency of the proposed method is particularly compared to the conventional Geigel algorithm and normalized cross-correlation method (NCC) that depends on the cross-correlation between the microphone signal and the error signal of AEC. Performance evaluation is confirmed by computer simulation.