A unified approach to IFIR filter design using B-spline functions

Abstract

An efficient procedure is presented for the design of interpolated finite impulse response (IFIR) filters with linear phase. The algorithm uses the uniform B-spline function as an interpolator and solves the optimal Chebyshev approximation problem on the appropriate subinterval. The technique can be used for the design of general low-pass, high-pass and bandpass filters. Although the number of multiplications of the IFIR filter is dependent on the bandwidth and the center frequency of the desired filter, this approach nearly always provides a substantial reduction in complexity when compared to other FIR and IFIR design procedures