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Efficient convex solution for 3-D localization in MIMO radars using delay and angle measurements
, Article IEEE Communications Letters ; Volume 23, Issue 12 , 2019 , Pages 2219-2223 ; 10897798 (ISSN) ; Amiri, R ; Behnia, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
In this letter, an efficient estimator for 3-D target localization in distributed multiple-input multiple-output (MIMO) radars using time delay (TD) and angle of arrival (AOA) measurements is proposed. First, an approximately equivalent maximum likelihood (ML) estimation problem is formulated. Then, the aforementioned ML problem is recast into a convex optimization problem for which we derive a semi closed-form solution that eventually boils down to finding the roots of certain polynomials. Using numerical simulations, we demonstrate that the proposed estimator reaches the Cramer-Rao lower bound (CRLB) up to relatively high Gaussian measurement noise levels. Furthermore, the proposed method...
Efficient elliptic localization in the presence of antenna position uncertainties and clock parameter imperfections
, Article IEEE Transactions on Vehicular Technology ; Volume 68, Issue 10 , 2019 , Pages 9797-9805 ; 00189545 (ISSN) ; Kazemi, S. A. R ; Behnia, F ; Noroozi, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
In this paper, an algebraic solution for elliptic localization in multiple-input multiple-output (MIMO) radar systems is proposed by taking the uncertainties in antenna positions and their clock parameters into account. Through nonlinear transformation and multi-stage processing, the target position is estimated in closed-form by successively utilizing the weighted least squares estimator. Theoretical analysis demonstrates that the proposed method is able to attain the Cramer-Rao lower bound (CRLB) performance under mild Gaussian error. The conditions for achieving the CRLB are derived as well. The numerical simulations confirm the analytical results and demonstrate significant performance...
An approximate ml estimator for moving target localization in distributed mimo radars
, Article IEEE Signal Processing Letters ; Volume 27 , 2020 , Pages 1595-1599 ; Amiri, R ; Behnia, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2020
Abstract
This letter deals with the problem of moving target localization in distributed multiple-input multiple-output (MIMO) radar systems using time delay (TD) and Doppler shift (DS) measurements. The proposed solution to this problem consists of two stages. In the first stage, an initial estimation of target location is obtained by solving the formulated maximum likelihood (ML) problem based on the TD measurements. In the second stage, by recognizing the obtained position estimate in the previous stage as a priori data and exploiting the DS measurements, another ML problem is formulated, which is efficiently solved via a tractable numerical method to produce a simultaneous estimation of target...
Efficient closed-form solution for 3-d hybrid localization in multistatic radars
, Article IEEE Transactions on Aerospace and Electronic Systems ; Volume 57, Issue 6 , 2021 , Pages 3886-3895 ; 00189251 (ISSN) ; Amiri, R ; Behnia, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
In this article, an algebraic solution for localizing a moving target using a nonstationary multistatic radar system is proposed. By utilizing the quadruple hybrid measurement set, which consists of time delay, Doppler shift, angle of arrival, and angle rate measurements, the proposed method can estimate the target position and velocity vectors via a simple one-stage weighted least squares estimator without the need for introduction of the nuisance parameters, which enables us to locate the target with the minimum number of antennas. The proposed estimator takes the uncertainty concerned with the position and velocity of the antennas in its design. The proposed estimator is shown to be...
Data association for multi-target elliptic localization in distributed MIMO radars
, Article IEEE Communications Letters ; Volume 25, Issue 9 , 2021 , Pages 2904-2907 ; 10897798 (ISSN) ; Amiri, R ; Behnia, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
In this letter, an efficient method for solving the multi-target localization problem in distributed MIMO radars is proposed. The proposed method attempts to simultaneously carry out the localization and data association tasks by formulating a mixed-integer optimization problem, which is approximated as a convex problem that can be efficiently solved with a polynomial complexity. Numerical simulations substantiate the efficacy of the proposed method. © 1997-2012 IEEE
Advanced damage detection technique by integration of unsupervised clustering into acoustic emission
, Article Engineering Fracture Mechanics ; 2018 ; 00137944 (ISSN) ; Chai, H. K ; GhasemiGol, M ; Sepehrinezhad, A ; Mousa, A. A ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
The use of acoustic emission (AE) technique for damage diagnostic is typically challenging due to difficulties associated with discrimination of events that occur during different stages of damage that take place in a material or a structure. In this study, an unsupervised kernel fuzzy c-means pattern recognition analysis and the principal component method were utilized to categorize various damage stages in plain and steel fiber reinforced concrete specimens monitored by AE technique. Enhancement of the discrimination and characterization of damage mechanisms were achieved by processing time and frequency domain data. Both domains (time and frequency) were taken into account to propose new...
Advanced damage detection technique by integration of unsupervised clustering into acoustic emission
, Article Engineering Fracture Mechanics ; Volume 210 , 2019 , Pages 212-227 ; 00137944 (ISSN) ; Chai, H. K ; GhasemiGol, M ; Sepehrinezhad, A ; Mousa, A. A ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
The use of acoustic emission (AE) technique for damage diagnostic is typically challenging due to difficulties associated with discrimination of events that occur during different stages of damage that take place in a material or a structure. In this study, an unsupervised kernel fuzzy c-means pattern recognition analysis and the principal component method were utilized to categorize various damage stages in plain and steel fiber reinforced concrete specimens monitored by AE technique. Enhancement of the discrimination and characterization of damage mechanisms were achieved by processing time and frequency domain data. Both domains (time and frequency) were taken into account to propose new...
A data modem for GSM adaptive multi rate voice channel
, Article Proceedings of IEEE East-West Design and Test Symposium, EWDTS 2013 ; 2013 ; 9781479920969 (ISBN) ; Hadavi, A. H ; Kazemi, R ; Behnia, F ; Sharif University of Technology
2013
Abstract
This paper considers the problem of digital data transmission through the Global System for Mobile communications (GSM). A data modem is presented that utilizes codebooks of Speech-Like (SL) symbols to transmit data through the GSM Adaptive Multi Rate (AMR) voice codec. Using this codebook of finite alphabet, the continuous vocoder channel is modeled by a Discrete Memory less Channel (DMC). A heuristic optimization algorithm is proposed to select codebook symbols from a database of observed human speech such that the capacity of DMC is maximized. Simulation results show that the proposed data modem achieves higher data rates and lower symbol error rates compared to previously reported...
Performance improvement of spread spectrum additive data hiding over codec-distorted voice channels
, Article European Signal Processing Conference ; Volume. 97, Issue. 9 , 2014 , pp. 2510-2514 ; ISSN: 22195491 ; Kazemi, R ; Behnia, F ; Akhaee, M. A ; Sharif University of Technology
2014
Abstract
This paper considers the problem of covert communication through dedicated voice channels by embedding secure data in the cover speech signal utilizing spread spectrum additive data hiding. The cover speech signal is modeled by a Generalized Gaussian (GGD) random variable and the Maximum A Posteriori (MAP) detector for extraction of the covert message is designed and its reliable performance is verified both analytically and by simulations. The idea of adaptive estimation of detector parameters is proposed to improve detector performance and overcome voice non-stationarity. The detector's bit error rate (BER) is investigated for both blind and semi-blind cases in which the GGD shape...
Secure data communication through GSM Adaptive Multi Rate voice channel
, Article 2012 6th International Symposium on Telecommunications, IST 2012 ; 2012 , Pages 1021-1026 ; 9781467320733 (ISBN) ; Hadavi, A. H ; Kazemi, R ; Behnia, F ; Sharif University of Technology
2012
Abstract
This paper considers the problem of digital data transmission through the Global System for Mobile communications (GSM) for security applications. A data modem is presented that utilizes codebooks of Speech-Like (SL) symbols to transmit data through the GSM Adaptive Multi Rate (AMR) voice codec. Using this codebook of finite alphabet, the continuous vocoder channel is modeled by a Discrete Memory less Channel (DMC). A heuristic optimization algorithm is proposed to select codebook symbols from a database of observed human speech such that the capacity of DMC is maximized. Using the DMC capacity, a lower bound on the capacity of the considered voice channel can be achived. Simulation results...
Covert communications through mobile voice channels
, Article IET Information Security ; Volume 10, Issue 3 , 2016 , Pages 156-164 ; 17518709 (ISSN) ; Rezaei, R ; Akhaee, M. A ; Behnia, F ; Sharif University of Technology
Institution of Engineering and Technology
2016
Abstract
The rapid development and growth of cellular mobile networks in recent years has made voice channels widely available almost everywhere. On the other hand, voice dedicated channels possess properties that make them ideal options for high priority real-time secure communications. Beside these realities, information embedding has gained remarkable attention in recent years due to its potential application in multimedia security. In this regard, this study aims to propose an efficient scheme for data hiding to show the feasibility of exploiting these channels for covert communications. To this end, the authors propose new suboptimal but practical schemes based on additive and multiplicative...
Joint detection of carrier frequency and direction of arrival of wide-band signals using sub-nyquist sampling and interferometric direction finding
, Article AEU - International Journal of Electronics and Communications ; Volume 139 , 2021 ; 14348411 (ISSN) ; Pezeshk, A. M ; Behnia, F ; Sadeghi, M ; Sharif University of Technology
Elsevier GmbH
2021
Abstract
The main task of a reconnaissance receiver is to acquire wide-band radio signals of the environment and extract their important parameters/information. Direction of arrival (DOA) and carrier frequency are the two most important parameters that a reconnaissance receiver should extract. To extract internal information of the signals such as signal modulation and coded information, complete reception of the signals is necessary. Sub-Nyquist sampling is used in this study for signal conversion from analog to digital with a much reduced sampling rate compared to the carrier frequency and, phase interferometery is used for direction finding. In jointly designing of sub-Nyquist sampling and phase...
Observations on the dynamics of bubble cluster in an ultrasonic field
, Article Nonlinear Dynamics ; Volume 72, Issue 3 , 2013 , Pages 561-574 ; 0924090X (ISSN) ; Zahir, H ; Yahyavi, M ; Barzegar, A ; Mobadersani, F ; Sharif University of Technology
2013
Abstract
The dynamics driven interaction between the bubbles in a cavitation cluster is known to be a complex phenomenon indicative of a highly active nonlinear as well as chaotic behavior in ultrasonic fields. By considering the cluster of encapsulated microbubble with a thin elastic shell in ultrasonic fields, in this paper, the dynamics of microbubbles has been studied via applying the methods of chaos physics. Bifurcation, Lyapunov exponent, and time series are plotted with respect to variables such as amplitude, initial bubble radius, frequency and viscosity. The findings of the study indicate that a bubble cluster undergoes a chaotic unstable region as the amplitude and frequency of ultrasonic...
Data hiding robust to mobile communication vocoders
, Article IEEE Transactions on Multimedia ; Volume 18, Issue 12 , 2016 , Pages 2345-2357 ; 15209210 (ISSN) ; Perez Gonzalez, F ; Akhaee, M. A ; Behnia, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016
Abstract
The swift growth of cellular mobile networks in recent years has made voice channels almost accessible everywhere. Besides, data hiding has recently attracted significant attention due to its ability to imperceptibly embed side information that can be used for signal enhancement, security improvement, and two-way authentication purposes. In this regard, we aim at proposing efficient schemes for hiding data in the widespread voice channel of cellular networks. To this aim, our first contribution is to model the channel accurately by considering a linear filter plus a nonlinear scaling function. This model is validated through experiments with true speech signals. Then we leverage on this...
Fault-tolerant Optical Network on Chip Using Multiple Paths
, M.Sc. Thesis Sharif University of Technology ; Hessabi, Shaahin (Supervisor)
Abstract
Today, global on-chip communications become a critical power bottle-neck in high-performance many-core architectures. The importance of power dissipation in NoCs along with power reduction capability of on-chip optical interconnects offers optical network-onchip (ONoC) as a novel technology solution which can introduce on-chip interconnection architecture with high transmission capacity and low power consumption. However, the basic elements that are used in ONoCs are very temperature-sensitive. This may lead to changes in their physical characteristics which will cause incorrectness in network’s functionality. In this thesis, we propose an approach that even the elements change physically...
MIMO Radars Waveform Design
, M.Sc. Thesis Sharif University of Technology ; Behnia, F (Supervisor)
Abstract
MIMO radar is a next generation radar which transmits arbitrary waveforms at each one of its apertures. It has been shown that design of waveforms for MIMO radars in order to synthesize a desired spatial beampattern, is mapped into a waveform correlation matrix (R) design in the narrowband case. Therefore, waveform design in MIMO radar for beamforming could be broken into two steps, namely correlation matrix design and waveform synthesis for achieving given R. As of now, given a desired beampattern or estimated location information of targets, calculating R has been modeled as an optimization problem like SDP. Also, in some special cases like rectangular beampattern, close form solutions for...
Data Communication and Watermarking Through Voice Channels
, Ph.D. Dissertation Sharif University of Technology ; Behnia, Fereidoon (Supervisor)
Abstract
Nowadays, swift development of cellular network with the increased penetration rate, have made mobile voice channels widely available almost everywhere with higher priority comparing to the other conventional channels, e.g., GPRS, EDGE, HSDPA and etc. Leveraging on this fact two important utilization can be considered. The first one is related to urgent transmitting of vital data. As mentioned earlier, since this channel deems to be available everywhere and, recalling its priority, it is even accessible in congestion condition, it can be exploited as an efficient way to transmit small volume of emergence data urgently. Transforming the crash data on the road is an example of utilizing such...
Localization of Active Aerial Targets Using Targets with Known Location
, M.Sc. Thesis Sharif University of Technology ; Behnia, Feridoon (Supervisor)
Abstract
Localization of radio, acoustic and vibration wave’s sources by passive systems has many applications in positioning systems, navigation systems, wireless sensor networks, defense, security, and geophysics. RSS, AOA, TDOA, and FDOA are some of the techniques available for passive localization. The performance of TDOA/FDOA techniques does not degrade with distance and multipath, but it may suffer from poor performance for narrowband signals. On the other hand, FDOA technique requires narrowband signals. Thus, the combination of TDOA and FDOA can be suitable for a much wider range of sources. In addition, the TDOA/FDOA method can provide more accurate interference source localization compared...
Increasing Operating Range of Wideband Reconnaissance Receivers, by Using Antenna Arrays
, Ph.D. Dissertation Sharif University of Technology ; Behnia, Fereidoon (Supervisor)
Abstract
Passive wideband reconnaissance receivers, listen to the radio and radar signals in the environment and estimate their important parameters such as direction of arrival (DOA). The wideband attribute for these receivers is to refer to their ability to receive wideband signals.Due to the use of processing gain, LPI radars reduce their transmitted signal power to see and not to be seen. On the other hand reconnaissance receivers can not have much processing gain, because they do not know the nature of the transmitted signal; Therefore, to increase the operational range of these systems, it is necessary to increase the signal to noise power ratio (SNR). This thesis examines the use of antenna...
Analysis of Effective Parameters in Localization Accuracy of Positioning Systems
, Ph.D. Dissertation Sharif University of Technology ; Behnia, Fereidoon (Supervisor)
Abstract
Target localization using positioning systems has long been considered by researchers in various fields.One of the important issues in localizing a target is the accuracy of its determined position. There are several parameters in the accuracy of position estimation. In a comprehensive view, these parameters can be divided into three general factors,including the relative geometry of the transmitters/receivers with respect to the target, the accuracy of measurements, and the type of target position estimator.The first factor, i.e. the relative geometry between the target and the transmit/receive antennas, plays an important role in localization accuracy. In the first part of this thesis, the...