A new structure for design narrow band lowpass FIR filters

Abstract

A new structure is proposed for design narrow band sharp lowpass FIR filters. The proposed structure is able to achieve significant savings in the number of multipliers and adders when combined with the interpolated finite impulse response (IFIR) technique. The savings are achieved by replacing the interpolator in an IFIR filter with a prefilter-equalizer. The implementation of the proposed prefilter is multiplication free which leads to low complexity and low cost. We have shown by an example that the proposed structure yields additional savings of 44% and 36% in the number of multipliers and adders, respectively, compared to the IFIR approach.