Extrapolated impulse response FIR filters

Abstract

An FIR filter structure with reduced hardware complexity is presented. It makes use of the quasi-periodic nature of the impulse response samples of low-pass and high-pass filters to extrapolate the filter length. Because of the reduced number of multipliers, it has lower roundoff noise power compared to the direct-form structure. In this technique, one period of the impulse response is realized accurately and the other periods with smaller magnitudes are realized as scaled versions of that period.