Stereophonic acoustic echo cancellation using spatial decorrelation

One of the main challenges for a stereophonic acoustic echo canceller is that it suffers from poor convergence which is caused by strong correlation between the input signals. In this paper, we propose a new decorrelation technique which adopts spatial decorrelation to address the problem without altering the input signals. In the scheme, the input signals are decomposed and projected into the signal subspace and the noise subspace. When the decorrelated signals are fed to the adaptive filters, the interchannel coherence between the input signals decreases significantly. The output signals of the adaptive filters are then combined together to yield the estimate of the microphone signal. Experiments in a real-world environment and performance comparison with state-of-the-art techniques are conducted to demonstrate the effectiveness of the proposed technique.