18 accepted papers
This work focuses on compressing vast amounts of time series data from IoT sensors while achieving low reconstruction error, at a low compression ratio (ratio of output data size to input data size), for efficient storage and transmission. We investigate two lossy compression techniques: Adaptive Pi…
Sweep spread carrier (S2C) acoustic communication uses wideband chirp waveforms as they are well suited for communicating in an undersea multipath environment. While the gradient heterodyne receivers in the S2C systems can handle the multipath arrivals, we show that they are extremely sensitive to a…
We address the problem of the beam split (B-SP) caused by the spatial wideband (SW) effect in intelligent reflecting surface (IRS) aided wideband systems. The SW effect arises when the signal delay across the IRS aperture is comparable to the system sampling time. This leads to a B-SP, wherein the I…
In wideband systems operating at mmWave frequencies, intelligent reflecting surfaces (IRSs) equipped with many passive elements can compensate for channel propagation losses. Then, a phenomenon known as the beam-split (B-SP) occurs in which the phase shifters at the IRS elements fail to beamform at…
This paper addresses the challenge of efficient and accurate channel parameter estimation for Orthogonal Time Frequency Space (OTFS) systems in doubly selective channels. The existing approaches perform well when the channel delay and Doppler shifts are integer multiples of the delay and Doppler res…
We consider the problem of jointly estimating the states and sparse inputs of a linear dynamical system using noisy low-dimensional observations. We exploit the underlying sparsity in the inputs using fictitious sparsity-promoting Gaussian priors with unknown variances (as hyperparameters). We devel…
The benefits of cell-free multiple-input multiple-output (CF MIMO) systems over traditional cellular systems, viz., a dramatic improvement of spectral efficiency (SE) and uniform quality of service, crucially depend on the quality of the estimated channels at the access points (APs). However, in a C…
In this paper, we consider intelligent reflecting surface (IRS) assisted opportunistic communications (OC), and present a comparative analysis of the system throughput over independent and identically distributed (i.i.d.) and line-of-sight (LoS) channels. In the system we consider, the phase configu…
Automotive radars at the Terahertz (THz) frequency band have the potential to be compact and lightweight while providing high (nearly-optical) angular resolution. In this paper, we propose a bistatic THz automotive radar that employs the recently proposed orthogonal chirp division multiplexing (OCDM…
A new variable bandwidth multicarrier (VBMC) waveform was presented in [1] for communicating over wideband rapidly time-varying multi-scale multi-lag (MSML) channels. Perfect channel state information was assumed to be available at the receiver in [1]. In this work, we address the problem of channel…
We consider a bistatic vehicular integrated sensing and communications (ISAC) system that employs the recently proposed orthogonal chirp division multiplexing (OCDM) multicarrier waveform. As a stand-alone communications waveform, OCDM has been shown to be robust against the interference in time-fre…
In this work, we consider control of linear dynamical systems using sparse inputs. We provide an algorithm for determining a sequence of sparse inputs that will take the system from any given initial state to a desired final state, and stay in that state thereafter. We formulate this as a sparse vec…
This paper presents a new tomography-based anomaly mapping algorithm for composite structures. The system consists of an array of piezoelectric transducers which sequentially excites the structure and collects the resulting waveform at the remaining transducers. Anomaly indices computed from the sen…
Disjunct matrices play a central role in non-adaptive group testing, as they provide necessary and sufficient conditions for identifying defective items from a large population using a small number of tests. In this paper, we show that binary disjunct matrices can also be very useful for recovering…
We consider the problem of recovering the common support of a set of k-sparse signals {x <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">i</sub> }L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">i=1</sub>…
We present computationally efficient and analytically tractable algorithms for identifying a given number of “non-defective” items from a large population containing a small number of “defective” items under a noisy Non-adaptive Group Testing (NGT) framework. In contrast to the classical NGT, where…
In this paper, we propose algorithms for finding the optimum multi-hop routes and corresponding transmit powers that maximize the throughput between a pair of device-to-device (D2D) nodes, under a constraint on the maximum interference caused to the cellular network. Our solution involves two steps.…
In this work, we address the recovery of sparse and compressible vectors in the presence of colored noise possibly with a rank-deficient noise covariance matrix, from overcomplete noisy linear measurements. We exploit the structure of the noise covariance matrix in a Bayesian framework. In particula…