Cascade-Form Multiplierless FIR Filter Design Using Orthogonal Genetic Algorithm

A genetic-algorithm (GA) based optimization approach for the design of multiplierless FIR filters is presented. The approach exploits a recently-introduced GA, called orthogonal GA (OGA), based on the so-called experimental design technique to obtain fixed-point implementations of linear-phase FIR filters. In the proposed approach, the filter coefficients are treated as chromosomes to be optimized and the effects of finite word length are minimized by considering the filter as a cascade of two sections. The OGA employs an integer encoding scheme for chromosome construction whereby the filter coefficients are expressed in terms of sums of powers of two to obtain the multiplierless design. The optimization is carried out by minimizing an objective function based on the amplitude response error. Experimental results show that the OGA approach leads to improved amplitude response relative to that of an equivalent direct-form cascade filter obtained using the Remez exchange algorithm