Fast and Efficient Sparse 2D Discrete Fourier Transform using Sparse-Graph Codes

no code implementations • 19 Sep 2015 • Frank Ong, Sameer Pawar, Kannan Ramchandran

For the case when the spatial-domain measurements are corrupted by additive noise, our 2D-FFAST framework extends to a noise-robust version in sub-linear time of O(k log4 N ) using O(k log3 N ) measurements.

Information Theory Multimedia Systems and Control Information Theory

SPRIGHT: A Fast and Robust Framework for Sparse Walsh-Hadamard Transform

3 code implementations • 26 Aug 2015 • Xiao Li, Joseph K. Bradley, Sameer Pawar, Kannan Ramchandran

We consider the problem of computing the Walsh-Hadamard Transform (WHT) of some $N$-length input vector in the presence of noise, where the $N$-point Walsh spectrum is $K$-sparse with $K = {O}(N^{\delta})$ scaling sub-linearly in the input dimension $N$ for some $0<\delta<1$.

A robust sub-linear time R-FFAST algorithm for computing a sparse DFT

no code implementations • 1 Jan 2015 • Sameer Pawar, Kannan Ramchandran

If the DFT X of the signal x has only k non-zero coefficients (where k < n), can we do better?