Synthesis of IIR digital filters exhibiting simultaneous amplitude and phase responses for VLSI implementations

A method is described for the design and implementation, in a double-lattice form, of selective linear phase digital filters. It is shown that these filters are optimum in the sense that all available degrees of freedom are used in adjusting the filter parameters to meet the specified characteristics. The designed filters, apart from satisfying the linear phase requirement, exhibit equiripple loss response over both the pass- and stopbands. A novel computationally efficient method based on computing the complex cepstrum is proposed for the construction of orthogonal double-lattice structures that realize the designed filters. It is based on the important property of cepstrum functions, namely decomposing mixed sequences into both minimum and maximum phase sequences. Illustrative examples are given to support the theoretical analysis. (C) 1997 John Wiley & Sons, Ltd.