Practical System Inversion Without Impulse Response Approximation

A procedure is described for finding the input sequence of a linear system given the output sequence. The system need not be minimum phase though it cannot have unit circle zeros. The method does not involve impulse response approximations, but does rely in the general case on the availability of a storage medium such as tape. Errors are introduced by initial or terminal condition effects but these are guaranteed to have decaying influence as one moves away from the initial or terminal time.