An improved cross-correlation spectral subtraction post-processing algorithm for noise and echo canceller

Conventional acoustic echo cancellation (AEC) system can remove a large amount of annoying echo. However, the residual echo usually exists which, together with the ambient noise, degrades the duplex speech communication quality. In this paper, a post-processing algorithm based on an improved crosscorrelation spectral subtraction (CCSS) method is proposed to further attenuate the residual echo as well as background noise. The proposed algorithm is able to obtain an optimal priori signal-to-noise ratio (SNR) estimate which is closer to the real situation by using an adaptive smoothing factor based on the minimum mean square error (MMSE) criterion. On the other hand, an adaptive subtraction factor leading to better performance can be obtained by using the prior SNR estimate instead of the tradition fixed parameter. Computer simulations are conducted to verify the advantages achieved by the proposed algorithm in removing the residual echo and background noise.

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