Design of nearly optimum power-of-two coefficient cascaded filters
A. Mahmood, J.R. Kunk · 2002
A design technique is developed for powers-of-two coefficient FIR filters that use two complementary filters in cascade. The two filters are designed to cancel out each other's errors in the frequency domain. Since the cascaded design results in a convolution of the individual filter's power-of-two coefficients, the combined filter's coefficients are much closer to the optimum real coefficients thus yielding a near optimum frequency response. The powers-of-two coefficients for the first filter are obtained by simple rounding from an optimal real coefficient design, and a localized search scheme is used for its cascaded complement. The design technique allows the desired frequency response to be approximated in the least square or the minimax sense.>