Optimization of FIR Filters Synthesized Using the Generalized One-Stage Frequency-Response Masking Approach

Frequency-response masking (FRM) approach is a very efficient technique for drastically reducing the number of multipliers and adders in implementing sharp linear-phase finite-impulse-response (FIR) digital filters. It has been shown that further savings in arithmetic operations can be achieved by using the generalized FRM approach, where the masking filters have a new structure. In both the original and the generalized synthesis techniques, the subfilters in the overall implementation are designed separately. The arithmetic complexity in the original one-stage FRM filter designs has been considerably reduced by using a two-step technique for simultaneously optimizing all the subfilters. Such an efficient algorithm was also proposed for synthesizing multistage FRM filters. This paper adapts this algorithm to the generalized one-stage FRM approach. An example taken from the literature illustrates that both the number of multipliers and adders for the resulting filters are approximately 60 percent compared with those of the filters designed using the original one-stage FRM technique