Design of Narrow Transition Band Digital Filter: An Analytical Approach

Abstract Frequency response masking (FRM) approach, is widely used to reduce the transition width of FIR filter which includes several advantages like lower coefficient sensitivity, higher computation speed and low power consumption. This paper proposes a novel interpolated bandpass method (IBM) for the synthesis of linear phase, narrow transition band FIR filter with less complexity. Simulation results have shown the magnitude response of several lowpass FIR filters with narrow transition bandwidth, as designed with the aid of proposed approach. Supremacy of the proposed algorithm has also been established in terms of frequency response characteristics and hardware complexity over a number of state-of-the-art techniques of recent interest. Simulation results have identified an improvement of ∼18.89%, 44.62%, 38.75%, 41.2% and 29.5% in terms of transition bandwidth when compared with several example filters under consideration. In addition to this, hardware cost resulting from the proposed narrow-band FIR filter is analyzed by implementing it on Artix field programmable gate array (FPGA) chip and consequently power consumption of the resulting filter has been estimated using Xilinx Power Estimator (XPE)-2018.1. Finally, the designed narrow transition band FIR filter is used in filtered-orthogonal frequency division multiplexing (F-OFDM) based quadrature amplitude modulated (QAM) system and the resultant bit error rate (BER) performance has been studied.