A modified imperialist competitive algorithm for digital IIR filter design

There are two major types of digital filters in terms of structure: infinite impulse response (IIR) and finite impulse response (FIR). Digital IIR filters often provide a much better performance and less computational cost than FIR filters and have become the target of growing interest. Since the problem of the error surface of designing digital IIR filters is generally nonlinear and multimodal, global optimization techniques are required in order to avoid local minima. In this paper, an evolutionary method has been proposed to design digital IIR filters. This method is based on Imperialist Competitive Algorithm (ICA) and by adding a step to the existing steps of ICA, performance of it has been improved in searching solution space and convergence to the global minima. Obtained results from simulation using proposed method and other algorithms show that the proposed method is suitable for designing digital IIR filter.