A novel algorithm for sparse FFT pruning and its applications to OFDMA technology

Abstract

This paper proposes novel DIF and DIT, FFT algorithms that utilizes data sparsity information to acheive sub-optimal computational complexity over traditional radix-2 FFT. Using the sparsity information, a map of the relavant nodes that would contribute to the FFT sum is first derived. Then the second part of the algorithm traverses this map and performs computation. This paper also provides the analysis of the computational complexity and how it can be tied in to existing frame work of OFDMA baseband. This algorithm is well suited for hardware efficient in-place FFT computations and especially for large size FFTs. The best application would be to use this algorithm in OFDMA basebands where the sparsity information can be known in advance.