Design and Implementation of Low Complexity 2-D Variable Digital FIR Filters Using Single-Parameter-Tunable 2-D Farrow Structure

Abstract

In this paper, a novel single-parameter-tunable 2-D Farrow structure is proposed and used for implementing linear phase 2-D variable digital filters (VDFs) with tunable spectral characteristics. Real-time tunability in the spectral characteristics of the 2-D filter is achieved by varying a single tunable parameter in a fixed hardware structure. The proposed structure enables the realization of multiple 2-D filters from a single structure with minimum error and hardware complexity. The reduction in the hardware complexity becomes pronounced when the number of 2-D filters included in the 2-D VDF increases. The proposed structure is capable of efficiently realizing circularly symmetric and fan-type variable 2-D filters, which is demonstrated using different design examples. Results show that the proposed approach ensures up to 60% reduction in the hardware complexity when compared with the state-of-the-art approaches used for the design and implementation of 2-D VDFs. The proposed approach ensures a drastic reduction in the hardware complexity without sacrificing the accuracy with a normalized root mean square error less than 0.5%.