Fixed length FIR filters with continuously variable bandwidth

Abstract

Software defined radios require filters of different bandwidths to process the many different bandwidth signals plucked from the other. Filters with different fractional bandwidth, fBW/fSMPL, have different lengths or number of taps, that varies inversely with the fractional bandwidth. Different length filters require different computational resources which include data registers, multipliers, and filter coefficients. This paper describes a filter architecture that supports variable bandwidth FIR filters with fixed computational resources.