An efficient split-radix FFT algorithm

In this paper, an efficient split-radix FFT algorithm is proposed for computing the length-2^r DFT that reduces significantly the number of data transfers, index generations, and twiddle factor evaluations or accesses to the lookup table. It is shown that the arithmetic complexity of the proposed algorithm is no more than that of the existing split-radix algorithm. The basic idea behind the proposed algorithm is that a radix-2 and a radix-8 index maps are used instead of a radix-2 and a radix-4 index maps as in the classical split-radix FFT. In addition, since the algorithm is expressed in a simple matrix form using the Kronecker product, it facilitates an easy implementation of the algorithm, and allows for an extension to the multidimensional case.