Gravitational Search Algorithm with Wavelet Mutation applied for optimal IIR band pass filter design

In this paper, an improved version of Gravitational Search Algorithm (GSA) called GSA with Wavelet Mutation (GSAWM) is applied for the design of 8th order infinite impulse response (IIR) band pass digital filter. Incorporation of mutation strategy into the conventional GSA technique not only enhances its searching capability but also the chance of convergence to near global solution is increased many folds. Apart from GSA, performance of the proposed optimization technique is compared with some well accepted evolutionary algorithms such as PSO and real coded genetic algorithm (RGA). From the simulation study it can be established that the proposed optimization technique GSAWM outperforms RGA, PSO and GSA, not only in the accuracy of the designed filter but also in terms of 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.