Local search algorithm for the design of multiplierless digital filters with CSD multiplier coefficients

This paper is concerned with the development of a technique for the optimization of digital filters over the canonical signed-digit (CSD) coefficient space. Although based on an existing local search algorithm, the proposed optimization technique does not make any recourse to the concept of an optimal scale factor. Consequently, it permits both the optimization of finite-impulse-response (FIR) digital filters (as is the case in the hitherto optimization techniques) as well as the that of the corresponding infinite-impulse response (IIR) digital filters. The usefulness of the proposed technique is demonstrated through its application to the optimization of a bandpass IIR and a lowpass FIR digital filter.