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Stereo acoustic echo suppression using widely linear filtering in the frequency domain

This paper proposes a stereo acoustic echo suppression method for duplex stereo teleconferencing. Firstly the stereo signals are combined in the frequency domain to build a single-channel signal. Secondly, with the single-channel signal model, an optimal Linearly Constrained Minimum Variance (LCMV) filter based on the Widely Linear theory is derived, which is applied on microphone signal directly to maximumly suppress the acoustic echo and preserve the quality of near-end signal. To estimate the normalized correlation vectors required in the LCMV filter, we employ an initial guess method, which doesn’t require double-talk detector and inter-channel pre-decorrelation. The experimental results verify that this method can preserve the near-end speech quality as well as the spatial information, and suppresses echo greatly.