Reducing the Hamming distance of encoded FFT twiddle factors using improved heuristic algorithms

This paper addresses the exploration of different heuristic algorithms for a better manipulation of twiddle factors of Fast Fourier Transform (FFT). The FFT algorithm involve multiplications of input data with appropriate coefficients, hence the best ordering of those operations can contribute for reducing the switching activity, what leads to the minimization of power consumption in FFTs. The heuristic algorithm named Bellmore and Nemhauser, and a proposed one named Anedma in both original and improved versions, are used to get as near as possible to the optimal solution for the ordering and partitioning of coefficients in FFTs. Data encoding methods are used for decreasing switching activity for transmitting information over buses, hence we have used some encoding techniques in the coefficients. As will be shown, the appropriate ordering of coefficients, based on the guidance given by the improved Anedma algorithm, can contribute for the reduction of Hamming distance of the encoded twiddle factors.