Design of IIR digital filters in the complex domain by transforming the desired response

In this paper, we present a new design method of IIR digital filters with equiripple magnitude response in the complex domain. This method is based on solving a least square solution iteratively. At each iteration, the desired response is transformed so as to have equiripple error. This algorithm is efficient because we don't need any initial value and any optimization. By this method, a equiripple solution is obtained very quickly with less computational complexity. Finally, we show some examples to validate the proposed method.