Design of highly selective quasi-equiripple FIR lowpass filters with approximately linear phase and very lowgroup delay

In this contribution, the design of approximately linear-phase, low delay and quasi-equiripple FIR lowpass filters is resumed with particular emphasis on very low group delay. To this end, a novel unconstrained single-objective multi-criterion design algorithm is proposed. Results show that the mean group delay can be diminished down to roughly 20%of that of a corresponding linear-phase FIR filter. Moreover, the application of the proposed algorithm to the design of power complementary (square-root Nyquist) filters is demonstrated.