BLIND SOURCE SEPARATION WITHOUT OPTIMIZATION CRITERIA?

Blind source separation aims to extract a set of independent signals from a set of observed linear mixtures. After whitening the sen-sor output, the separation is achieved by estimating an orthogonal transformation, which in the real-mixture two-source two-sensor case is entirely characterized by a single rotation angle. This con-tribution studies an estimator of such an angle. Even though it is derived from geometric notions based on the scatter-plots of the signals involved, it is found, empirically, to exhibit a perfor-mance clearly up to the mark of other methods based on opti-mality criteria and, theoretically, to improve and generalize one of such procedures. The simplicity of the suggested estimator results in a straightforward adaptive version, which converges regardless of the source distribution, for quite mild conditions, and whose asymptotic analysis is easy to carry out. The applicability of the estimator in a full separation system is also illustrated. 1