(Nearly) Sample-Optimal Sparse Fourier Transform in Any Dimension; RIPless and Filterless
In this paper, we consider the extensively studied problem of computing a k-sparse approximation to the d-dimensional Fourier transform of a length n signal. Our algorithm uses O(k log k log n) samples, is dimension-free, operates for any universe size, and achieves the strongest ℓ_∞/ℓ_2 guarantee, while running in a time comparable to the Fast Fourier Transform. In contrast to previous algorithms which proceed either via the Restricted Isometry Property or via filter functions, our approach offers a fresh perspective to the sparse Fourier Transform problem.