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The problem of joint Angle-of-Arrival (AoA) and calibration parameters in a wideband scenario is addressed. The system consists of multiple sources transmitting from different directions and in certain subcarriers. Sources in the same beam are regarded as transmitted from the same AoA and their signals are allocated to different subcarriers while users in different beams may transmit on the same subcarrier,...
The problem of Angle-of-Arrival estimation of multiple sources in the presence of mutual coupling is addressed. The presence of unknown mutual coupling between antenna array elements is known to degrade the performance of direction-finding algorithms. We first present a result explaining why some traditional methods, that estimate Angles-of-Arrival (AoAs) of multiple sources in the presence of mutual...
The problem of Angle-of-Arrival estimation of multiple sources in the presence of mutual coupling is addressed. In this paper, we derive a Mean-Squared-Error (MSE) expression of a recently proposed algorithm that could estimate the Angles-of-Arrival of multiple sources in the presence of more mutual coupling parameters, compared to traditional methods. The MSE expression is compared with the MSE of...
This paper presents an iterative Variational Bayes (VB) algorithm that allows sparse recovery of the desired transmitted vector. The VB algorithm is derived based on the latent variables introduced in the Bayesian model in hand. The proposed algorithm is applied to the Angle-of-Arrival (AoA) estimation problem and simulations demonstrate the potential of the proposed VB algorithm when compared to...
A novel approach entitled “Joint Angle and Delay Estimator and Detector”, or simply JADED, is presented. This approach allows simultaneous estimation of number of coherent/non-coherent sources and joint estimation of the angles and times of arrival of each source. The system is composed of a Uniform Linear Array (ULA) receiving known OFDM symbols from a user in an indoor environment, which is rich...
The problem of Angle of Arrival estimation of multiple sources in the presence of mutual coupling is addressed. The presence of unknown mutual coupling between antenna array elements is known to degrade the performance of super resolution direction-finding algorithms. In this paper, we propose an iterative algorithm based on Alternating Projection in order to optimise the Maximum Likelihood cost function,...
The problem of Joint Angle and Delay Estimation (JADE) in the presence of mutual coupling is addressed. The system consists of a Single Input Multiple Output (SIMO) link in an OFDM communication setting. This paper presents two resilient algorithms that could cope with mutual coupling. The first one is an extension of an existing algorithm in order to perform JADE, which allows resolvability of more...
We investigate the performance of some sparse recovery and compressed sensing algorithms when applied to the Angle-of-Arrival (AoA) estimation problem. In particular, we review three different approaches in compressed sensing, namely Pursuit-type, Thresholding-type, and Bayesian-based algorithms. The compressed sensing algorithms reviewed herein are of vast interest when applied to AoA estimation...
A novel algorithm for estimating the Angles of Arrival (AoA) of multiple sources in the presence of mutual coupling is derived. We first formulate an “Equality Constrained Quadratic Optimisation” problem, then derive a suitable MUSIC-like algorithm to solve the aforementioned problem, and thus obtain good estimates of the AoA parameters. Identifiability conditions of the proposed algorithm are also...
Two algorithms for the problem of joint angles and delays of arrival (JADE) of multiple paths are presented. The algorithms are based on a generalisation of the Matrix Pencil algorithm to the two dimensional case, i.e. 2D Matrix Pencils. Matrix pencil algorithms offer estimation of signal parameters, i.e. angles of arrival (AoA) or times of arrival (ToA), of multiple sources using a single snapshot...
We present a novel 2D-MUSIC algorithm that can jointly estimate the angles and times of arrival of multiple signals in the presence of local scattering. We focus on a scenario where the received signal is a sum of “clusters”, and each cluster is composed of multi-incident rays that show similar angles and times of arrival. The setting is composed of a Single-Input-Multiple-Output (SIMO) link where...
The problem of estimating the number of superimposed signals using noisy observations from N antennas is addressed. In particular, we are interested in the case where a low number of snapshots L = O(N) is available. We focus on the Minimum Description Length (MDL) estimator, which is revised herein. Furthermore, we propose a modified MDL estimator, with the help of random matrix tools, which improves...
A natural extension of the "Spatial" smoothing preprocessing technique is presented and analysed. It is well known that subspace methods do not work properly in the presence of coherent sources. In this paper, a "Spatio-Frequential" smoothing technique is described when the transmit OFDM symbol is received through multiple coherent signals using a uniform linear antenna array....
This paper presents and analyses two computationally attractive Maximum Likelihood (ML) estimators for joint Angle of Arrival (AoA) and Time of Arrival (ToA) of a Single Input Multiple Output (SIMO) link in an OFDM communication setting. We consider a rich multipath channel, which is the case of an indoor environment, where the received signal is a sum of scaled and delayed versions of the original...
In this paper, we focus on joint multipath angle and delay estimation (JADE) in an OFDM communication setting. We analyse the effect of Gaussian random snapshot (OFDM symbol) timing jitter on the spatio-frequency sample covariance matrix containing delay and direction information. This sample covariance matrix is an input to the JADE and many other algorithms for signal parameter estimation. The analysis...
Zero-day exploits against servers pose one of the most challenging problems faced by system and security administrators. Current solutions rely mainly on signature databases of known attacks and are not efficient at detecting new attacks not covered by their attack signature database. We propose using a dummy server, i.e. A mirror of the server to be protected but without the real data. Consequently,...
Attackers are increasingly relying on non-executable files to launch their attacks. Anti-virus solutions can detect a high percentage of malicious files but usually cannot reach and maintain a 100% detection rate. We propose a file-level IDS that relies on automated dynamic analysis system (sandbox) to detect malicious PDF files. We achieved a 99.2% detection rate, where the rates of both the false...
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