Multi-Delay Sparse Approach to Residual Crosstalk Reduction for Blind Source Separation

Abstract

For reducing residual crosstalk in the output of blind source separation, we propose a frequency-domain post-filtering method that uses a multi-delay model of complex-valued residual crosstalk and sparsifies the estimates of the source signals. We formulate the reduction of residual crosstalk as an optimization problem using $\ell _1$ norm and solve it using the alternating direction method of multiplier. The proposed method improved the source-to-interference ratio from 17.8 to 20.5 dB and the source-to-distortion ratio from 10.2 to 11.3 dB when it was combined with a brute-force solver of FastICA and reverberation time $T_{60}$ was 300 ms.