Multiplierless Unified Architecture for Mixed Radix-2/3/4 FFTs

Abstract

This paper presents a novel runtime-reconfigurable, mixed radix core for computation 2-, 3-, 4- point fast Fourier transforms (FFT). The proposed architecture is based on radix-3 Wingorad Fourier transform, however multiplication is performed by constant multiplication instead of general multiplier. The complexity is equal to multiplierless 3-point FFT in terms of adders/subtractors with the exception of a few additional multiplexers. The proposed architecture supports all the FFT sizes which can be factorized into 2, 3, 4 point systems. We also show that the proposed architecture has the same bound on the accuracy as the classical one.