Publications/Signal Processing

Low-Frequency Electromagnetic Imaging Using Sensitivity Functions and Beamforming

We present a computational technique for low-frequency electromagnetic imaging in inhomogeneous media that provides superior three-dimensional resolution over existing techniques. The method is enabled through large-scale, fast (low-complexity) algorithms that we introduce for simulating electromagnetic wave propagation. We numerically study the performance of the technique on various problems including the

05/05/2020

Passive Tracking of Objects Using Bistatic Dual-Polarization Receivers

A system for detecting and/or tracking a moving object uses signals received from the object at two or more receivers, each of which is dual polarized. At each receiver, the component of the received signal associated with the polarization thereof is separated from the non-polarization-based component, and the modulation of

10/22/2019

Fast Large-Scale Algorithm for Electromagnetic Wave Propagation in 3D Media

We present a fast, large-scale algorithm for the simulation of electromagnetic waves (Maxwell’s equations) in three-dimensional inhomogeneous media. The algorithm has a complexity of O(N log(N)) and runs in parallel. Numerical simulations show the rapid treatment of problems with tens of millions of unknowns on a small shared-memory cluster (

09/24/2019

Systems and Methods for Communication Using Sparsity Based Pre-Compensation

A signal pre-compensation system analyzes one or more properties of a communication medium and, taking advantage of the locality of propagation, generates using sparse fast Fourier transform (sFFT) a sparse kernel based on the medium properties. The system models propagation of data signals through the medium as a fixed-point iteration

10/09/2018

A Sparse Multi-Dimensional Fast Fourier Transform with Stability to Noise in the Context of Image Processing and Change Detection

We present the sparse multidimensional FFT (sMFFT) for positive real vectors with application to image processing. Our algorithm works in any fixed dimension, requires an (almost) – optimal number of samples and runs in complexity (to first order) for unknowns and nonzeros. It is stable to noise and exhibits an

09/13/2016

A Sparse Multidimensional FFT for Real Positive Vectors

We present a sparse multidimensional FFT (sMFFT) randomized algorithm for positive real vectors. The algorithm works in any fixed dimension, requires an (almost)-optimal number of samples (O (R log (N))) and runs in O (R log (N)) complexity (where N is the total size of the vector in d dimensions

05/10/2016

Embedded Second-Order Cone Programming with Radar Applications

Second-order cone programming (SOCP) is required for the solution of underdetermined systems of linear equations with complex coefficients, subject to the minimization of a convex objective function. This type of computational problem appears in compressed radar sensing, where the goal is to reconstruct a sparse image in a generalized space

09/01/2015

Re-Introduction of Communication-Avoiding FMM-Accelerated FFTs with GPU Acceleration

As distributed memory systems grow larger, communication demands have increased. Unfortunately, while the costs of arithmetic operations continue to decrease rapidly, communication costs have not. As a result, there has been a growing interest in communication-avoiding algorithms for some of the classic problems in numerical computing, including communication-avoiding Fast Fourier

09/01/2013

Low-Frequency Electromagnetic Imaging Using Sensitivity Functions and Beamforming

Passive Tracking of Objects Using Bistatic Dual-Polarization Receivers

Fast Large-Scale Algorithm for Electromagnetic Wave Propagation in 3D Media

Systems and Methods for Communication Using Sparsity Based Pre-Compensation

A Sparse Multi-Dimensional Fast Fourier Transform with Stability to Noise in the Context of Image Processing and Change Detection

A Sparse Multidimensional FFT for Real Positive Vectors

Embedded Second-Order Cone Programming with Radar Applications

Re-Introduction of Communication-Avoiding FMM-Accelerated FFTs with GPU Acceleration

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