Abstract

The paper develops a soft computing technique to solve the problem of designing an optimal digital infinite-impulse response (IIR) filter. In this paper a nature inspired optimization methodology is proposed for the robust and stable design of high order LP digital IIR filter. Particle Swarm Optimization (PSO) technique is applied to design the optimal digital IIR filter in order to avoid local minima as the error surface of IIR filters is multi-modal and non-linear. PSO utilizes a global search method, which utilizes a set of particles that move through the hyperspace to find the global minima of the objective function. The main objective of the optimization process is to find the filter coefficients approximately close to the desired filter response. To obtain our design criterion approximation magnitude error and ripple magnitudes of both pass-band and stopband. The magnitude response and the stability of the filter are determined by using Matlab. The pole-zero plot of the filter, describe the stability of the predesigned filter. This technique can also be used for the design of HP, BP and BS digital IIR filters.