ashok@atrp.mit.edu (Ashok C. Popat) (09/06/90)
Two questions about filters: Suppose I have a filter with impulse response h(n), having nonzero values only in the range 0 <= n <= N-1. I am interested in finding: (1) An approximate "square root" of this filter, in the convolution sense. That is, I am looking for a filter with impulse response f(n), which, when convolved with itself, approximates h(n). In my application, this filter need not be FIR, nor must it have a rational system function, but it must be stable and have negligible energy far away from the origin. (2) An approximate FIR inverse of the filter. That is, I am looking for a filter with finite-extent impulse response g(n) such that g(n) convolved with h(n) yields an approximation to the unit impulse. I mean "approximate" in the sense that the maximum absolute error or similar measure, should be minimized. In particular, I am not interested in a least-squares solution to (2). Any help or pointers to pertinent literature will be greatly appreciated. Please email replies to ashok@atrp.mit.edu; I'll summarize. Ashok Chhabedia Popat Swiss Federal Institute of Technology, Lausanne