Finite-time-domain synthesis of recursive linear time-variant causal digital filters by separable sequences

A method is given to synthesize a desired linear time-variant (LTV) digital filter given in numerical form in a finite time domain by a separable sequence of a given order. The method finds the separate sequence by alternately using two nonlinear restrictions that an optimal recursive LTV filter approximating the desired filter must satisfy. The performance of the proposed method is illustrated and compared with other available ones through numerical examples. The results of the comparisons show that the author´s method provides smaller synthesis errors than the others