A TECHNIQUE FOR MULTIPLE CRITERION APPROXIMATION OF FIR FILTERS IN MAGNITUDE AND GROUP DELAY

In spite of the attention received by nonlinear phase (NLP) FIR filter design, the ''best'' way to solve this problem is still open to debat e. The formulation of nonlinear phase FIR filter design in terms of si multaneous magnitude and group-delay approximation addresses the two p arameters of ultimate interest for applications. The simultaneous mini mization of these two functions (one of which, the group delay, ration al) is approached on the basis of an original extension of the differe ntial correction algorithm. The proposed design tool enjoys interestin g theoretical properties and works very effectively. The filters obtai ned according to the multiple criterion optimization (MCO) formulation are compared against filters that are optimal in the complex Chebyche v norm. Then, the flexibility characteristic of MCO formulations of tr ading off between magnitude and group-delay performance is exemplified .