A state space approach to the inverse of LPTV filters

In this paper, a state space approach for computing the inverse of a general single-input single-output linear periodically time-varying filter is proposed. The inverse of the filter is derived by first constructing the inverse of an LPTV filter. The result is then extended to obtain the inverse of the IIR filter. Compared with existing approaches using other techniques, the proposed approach is quite straightforward, hence, can reduce the computational complexity.