Heuristic Search Method for Digital IIR Filter Design

The paper develops innovative methodology for robust and stable design of digital infinite impulse response (IIR) filters using a heuristic search method. The proposed heuristic search method enhances the capability to explore and exploit the search space locally as well globally to obtain optimal filter design parameters. A multicriterion optimization is employed as design criterion to obtain optimal stable IIR filter that satisfies different performance requirements like minimizing Lp-norm approximation error and ripple magnitude. Multicriterion optimization problem has been solved applying weighted sum method and p-norm method. Best weight pattern is searched using evolutionary search method that minimizes the performance criteria simultaneously. The proposed heuristic search method is effectively applied to solve the multicriterion, multiparameter optimization problems of low-pass, high-pass, band-pass, and band-stop digital filters design. The computational experiments show that the proposed heuristic search method is superior or atleast comparable to other algorithms and can be efficiently used for higher filter design. Key-Words: Digital infinite impulse response filters, Heuristic search algorithm, Multicriterion optimization, Magnitude Response, Stability, Lp-norm error.