Independent component analysis employing exponentials of sparse antisymmetric matrices

摘要

Independent component analysis (ICA) is a standard method for separating a multivariate signal into additive components that are non-Gaussian and independent from each other. This paper introduced a novel algorithm to perform ICA employing matrix exponentials, which performs similarly to geodesic based methods but based on a different insight. First, we showed that the ICA problem can be formulated as an optimization problem in the space of orthogonal matrices whose determinants are one, which can be further transformed into an equivalent problem in the space of antisymmetric matrices. Then, an efficient approach was presented for iteratively solving this problem using the antisymmetric matrices with one or more nonzero columns and rows. Especially, we proved that in the sense of local optimization it is sufficient to employ antisymmetric matrices with only one nonzero column and row. The analytical expressions of exponentials of such special antisymmetric matrices were also explicitly established in this paper. Compared to other competing algorithms, experimental results indicated that the proposed method can achieve separation with superior performance in term of the precision and running speed. (C) 2018 Elsevier B.V. All rights reserved.