Digital stable IIR high pass filter optimization using PSO-CFIWA

In this paper, an optimal design of stable digital high pass infinite impulse response (IIR) filter using Particle Swarm Optimization with Constriction Factor and Inertia Weight Approach (PSO-CFIWA) has been presented. The conventional gradient based optimization techniques are not efficient enough for handling digital IIR filter design due to the sub-optimality problem. The proposed optimization technique PSO-CFIWA is a heuristic search algorithm and capable enough to handle non differentiable optimization problem to find optimal solution in multidimensional search space. Performance of the proposed algorithm is compared with well accepted evolutionary algorithms such as particle swarm optimization (PSO) and real coded genetic algorithm (RGA). From the simulation study it is established that the PSO-CFIWA outperforms RGA and PSO, not only in the accuracy of the designed filter but also in the convergence speed and solution quality i.e. the stop band attenuation, transition width, pass band and stop band ripples. Further, the pole-zero analysis justifies the stability of the designed optimized IIR filter.