Minimal square spectral factors

Abstract Recently there has been renewed interest in the problem of spectral factorization and in particular, the problem of parametrizing all square minimal spectral factors of a given spectrum. For instance, let us mention two recent papers in this journal, one of which dealing with more computational aspects of this problem (Clements, 1993), the other giving a parametrization under additional constraints (Ferrante et al., 1993). This paper is motivated in a large part by (Ferrante et al., 1993), in fact we shall show that a parametrization similar to the one given there can be achieved without one of the additional constraints imposed in (Ferrante et al., 1993). A secondary aim of this paper is to give an overview of several parametrizations available in the literature.

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