FIR approximation of fractional sample delay systems

This brief examines the approximation of fractional delays by FIR systems using various techniques which have previously been reported in the literature. In particular, the equivalence of the time-domain Lagrangian interpolation, the frequency-domain maximally flat error criterion and the window method is shown, provided maximal flatness is specified at /spl omega//sub 0/=0 and the window used is a scaled binomial function. The first of these has been known before, the second equivalence is new.