Clock Skew Robust Acoustic Echo Cancellation

Traditional acoustic echo cancelers require that the reference and microphone signals have exactly the same sampling frequency. In this paper, we present a novel Kalman filtering approach to acoustic echo cancellation (AEC) which blindly accounts for the clock skew between the playback and recording devices without the need for exchanging timestamps when they have independent clocks. The proposed Kalman-filter AEC employs a state-space formulation for the clock-skew problem and is implemented in a subband-domain based on our proposed novel variation of the complex modified discrete cosine transform which allows for arbitrary hop size and therefore enhanced time resolution. We show that the proposed algorithm is robust to Gaussian and super-Gaussian near-end noises and provide experimental results which demonstrate the state-of-the-art echo cancellation performance of the approach under clockskew conditions.