The primary difficulties of both the time-domain switch decomposition method and the frequency-domain decomposition method are overcome by introducing certain matrix operators and performing spectral factorization of resulting matrices of polynomials in the

-transform variable. Topological operations of the switch-decomposition method are simplified. This new approach eliminates the need to solve a system of equations with rational polynomial coefficients such as arises in the frequency-decomposition method. The determination of a multirate sampled-data system\´s characteristic polynomial no longer requires the evaluation of a determinant of rational polynomial elements. New results on obtaining modified

-transforms from standard

-transforms at a faster rate and vice versa are presented.