  In this article, nonstationary mixing and source models are combined for
developing new fast and accurate algorithms for Independent Component or Vector
Extraction (ICE/IVE), one of which stands for a new extension of the well-known
FastICA. This model allows for a moving source-of-interest (SOI) whose
distribution on short intervals can be (non-)circular (non-)Gaussian. A
particular Gaussian source model assuming tridiagonal covariance matrix
structures is proposed. It is shown to be beneficial in the frequency-domain
speaker extraction problem. The algorithms are verified in simulations. In
comparison to the state-of-the-art algorithms, they show superior performance
in terms of convergence speed and extraction accuracy.
