Extension of score function difference for frequency domain blind source separation

Recent theoretical developments in the field of blind source separation (BSS) introduced the score function difference (SFD) and showed its close relationship with the differential of the mutual information. These results are of great interest for developing BSS methods since the mutual information can be seen as the canonical cost function for BSS. However these results were only proposed in the real case. In this paper, we extend these results to the complex case and propose a frequency domain approach of BSS based on the complex equivalent of the SFD.