A paramount approach to design FIR filters for reduced complexity

Abstract

Finite-length impulse response (FIR) filters offer several good properties, like guaranteed stability and exact linear phase; however they require a higher filter order to fulfill a given specification as compared to Infinite-length impulse response (IIR) filters, especially when the transition band is relatively narrow. In this paper a model is proposed to design FIR filter by modifying the MLSE (Mean Least Square Error) method. This model brings significant reduction in the order of FIR filter as compared to other methods of FIR filter designing. This obtained FIR filter is insensitive to bit variation in filter coefficient length up to 5-bit. Not only the magnitude response, but also the Group delay response retains its shape for 99.5% of the normalized frequency band.