Use of Common Parts in Masking Filters for Complexity Reduction in FRM-Based FIR Filters

A very efficient technique for significantly reducing the number of multipliers and adders in implementing narrow transition band linear-phase finite-impulse response (FIR) digital filters is to use the frequency-response masking (FRM) approach. This paper studies the construction of the masking filter pair in the FRM technique using a common part for further reducing the arithmetic complexity. Extensive simulations are included showing that the use of the common part always considerably decreases the arithmetic complexity at the expense of a slight increase in the overall filter order.