FPGA implementation of low-power split-radix FFT processors

Abstract

Fast Fourier Transform (FFT) is one of the fundamental operations in digital signal processing area. Splitradix Fast Fourier Transform (SRFFT) approximates the minimum number of multiplications by theory among all the FFT algorithms, therefore SRFFT is a good candidate for the implementation of a low power FFT processor. In this PhD work, we aim to implement a novel low power Split-Radix FFT processor using shared-memory architecture and extend this work to a parallel structure based on FPGA. We started by designing a new radix-2 butterfly unit using clock gating approach to block unnecessary switching activity in the multiplier. Compared to existing SRFFT processors which are based on the “L” shaped butterfly, our implementation simplifies the address generation process for FFT data. Furthermore, because the number of multiplications required by SRFFT algorithm significantly decreases as the FFT size increases, it is reasonable to assume the proposed architecture will save more power when it comes to larger points of FFT.