Issues in frequency domain blind source separation - a critical revisit

One of the most important problems in frequency domain blind source separation (FDBSS) is the inconsistency across frequency in the permutation of the source estimates. According to previous studies, this problem can be reduced significantly by constraining the length of the unmixing filters. This improvement has been attributed to the smoothing of the unmixing frequency response. In this paper we study the effect of modifying these length constraints taking into account the circularity of the IDFT, and we show that the smoothing of the unmixing frequency response alone can not account for the improvements in performance.