B-SPLINE FIR FILTERS

This paper presents an efficient procedure for the design of interpola ted FIR (IFIR) filters with linear phase. The algorithm uses the unifo rm B-spline function as an interpolator and solves the optimal Chebysh ev approximation problem on the optimal subinterval. The technique can be used for the design of general lowpass, highpass and bandpass filt ers. While the number of multiplications of the IFIR filter is depende nt on the bandwidth and the center frequency of the desired filter, it provides the minimum number of multiplications achievable and nearly always provides a substantial reduction when compared to Parks-McClell an designs.