Complex Chebyshev approximation for IIR digital filters

This paper presents an efficient method for designing complex IIR digital filters in the complex Chebyshev sense. The proposed method is based on the formulation of a generalized eigenvalue problem by using the Remez multiple exchange algorithm. Hence, the filter coefficients can be easily obtained by solving the eigenvalue problem to find the absolute minimum eigenvalue, and then the complex Chebyshev approximation is attained through a few iterations starting with a given initial guess. The proposed algorithm is computationally efficient. One example is designed and compared with one proposed by Chen and Parks. It is shown that the results obtained by using the method proposed in this paper are better than the conventional methods