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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...
Spectral estimation by computationally reduced Kalman Filter
, Article Circuits, Systems, and Signal Processing ; Volume 31, Issue 6 , 2012 , Pages 2205-2220 ; 0278081X (ISSN) ; Rasouli, M ; Behnia, F ; Sharif University of Technology
2012
Abstract
This paper introduces an innovative frequency estimation approach that relies on a new and innovative structure for Kalman Filter (KF) in signal processing. Kalman Filtering, because of its state estimating nature, excels other methods in realtime processing. However, the main drawback of Kalman Filtering is that it involves time-consuming matrix operations which makes it inferior to faster methods like fast Fourier transform (FFT). The most evident privilege of the new structure is that it "synthesizes" the components rather than "extracts" them as standard Kalman Filter does. This parallel synthesis of signal components reduces the computational order of the Kalman Filter dramatically. In...
Autoregressive modeling of the photoplethysmogram AC signal amplitude changes after flow-mediated dilation in healthy and diabetic subjects
, Article 2012 19th Iranian Conference of Biomedical Engineering, ICBME 2012 ; 2012 , Pages 170-173 ; 9781467331302 (ISBN) ; Zahedi, E ; Behnia, F ; Sharif University of Technology
2012
Abstract
It is proved that the endothelial (artery inner lumen cells) function is associated with cardiovascular risk factors. Among all the common non-invasive methods employed in the research setting for assessing endothelial function, flow-mediated dilation is the most widely used one. This technique measures endothelial function by inducing reactive hyperemia using temporary arterial occlusion and measuring the resultant relative increase in blood vessel diameter via ultrasound. In this paper, the limitations associated with the ultrasound technique are overcome by using the photoplethysmogram (PPG) signal recorded during FMD. The correctness of this approach is investigated by modeling the AC...
Constrained optimization of sensors trajectories for moving source localization using TDOA and FDOA measurements
, Article International Conference on Robotics and Mechatronics, ICROM 2015, 7 October 2015 through 9 October 2015 ; 2015 , Pages 200-204 ; 9781467372343 (ISBN) ; Hamdollahzadeh, M ; Behnia, F ; Sharif University of Technology
2015
Abstract
This paper examines the problem of determining optimal sensors trajectories for localization of a moving radio source based on Time Difference of Arrival (TDOA) and Frequency Difference of Arrival (FDOA) measurements in situations in which sensors are constrained both in their movements and regions of operation. By considering the movement of the source and constrained movement of the sensors, a constraint problem is formed which is solved to determine optimal trajectories of the sensors for source tracking. The validity of the proposed algorithm is assessed by two different simulation scenarios and the results verify its proper operation with estimation error decreasing in consecutive steps...
Compressive sensing for elliptic localization in MIMO radars
, Article 24th Iranian Conference on Electrical Engineering, 10 May 2016 through 12 May 2016 ; 2016 , Pages 525-528 ; 9781467387897 (ISBN) ; Amiri, R ; Behnia, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016
Abstract
In this paper, a sparsity-aware target localization method in multiple-input-multiple-output (MIMO) radars by utilizing time difference of arrival (TDOA) measurements is proposed. This method provides a maximum likelihood (ML) estimator for target position by employing compressive sensing techniques. Also, for fast convergence and mitigating the mismatch problem due to grid discretization, we address a block-based search coupled with an adaptive dictionary learning technique. The Cramer-Rao lower bound for this model is derived as a benchmark. Simulations results are included to verify the localization performance
Recursive sensor placement in two dimensional TDOA based localization
, Article 24th Iranian Conference on Electrical Engineering, 10 May 2016 through 12 May 2016 ; 2016 , Pages 300-304 ; 9781467387897 (ISBN) ; Adelipour, S ; Behnia, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016
Abstract
This paper presents a new approach to sensor placement strategy in emitter localization problem which is based on Time Difference of Arrival (TDOA) measurements. The advantage of this method is its flexibility and capability of positioning sensors in constrained or non-stationary situations in which the positions of the sensors are restricted to certain portions of the space and/or needed to be changed repeatedly. The validity of the proposed algorithm is assessed by three different simulation scenarios and the results verify its proper operation
Optimal and robust waveform design for MIMO radars in the presence of clutter
, Article Signal Processing ; Volume 90, Issue 4 , April , 2010 , Pages 1103-1117 ; 01651684 (ISSN) ; Namvar, M ; Behnia, F ; Sharif University of Technology
2010
Abstract
Waveform design for target identification and classification in MIMO radar systems has been studied in several recent works. While the previous works assumed that the noise was independent of the transmission signals, here we extend the results to the signal dependent noise (clutter). We consider two scenarios. In the first scenario it is assumed that different transmit antennas see uncorrelated aspects of the target. In the second scenario, we consider the correlated target. As clutter is dependent to signal, target estimation error cannot vanish only by increasing the transmission power. It can be shown that in the second scenario, MIMO radar receiver can nullify the clutter subspace....
Optimal sensor configuration for two dimensional source localization based on TDOA/FDOA measurements
, Article Proceedings International Radar Symposium, 10 May 2016 through 12 May 2016 ; Volume 2016-June , 2016 ; 21555753 (ISSN) ; 9781509025183 (ISBN) ; Adelipour, S ; Behnia, F ; Sharif University of Technology
IEEE Computer Society
2016
Abstract
The Cramer-Rao lower bound for source localization based on Time Difference of Arrival and Frequency Difference of Arrival is investigated in this paper. The result is used for theoretical analysis of optimality in sensor placement. An optimal sensor-target geometry including sensors locations and velocities is presented and its properties is studied
Sequential sensor placement in twodimensional passive source localisation using time difference of arrival measurements
, Article IET Signal Processing ; Volume 12, Issue 3 , 2018 , Pages 310-319 ; 17519675 (ISSN) ; Adelipour, S ; Behnia, F ; Sharif University of Technology
Institution of Engineering and Technology
2018
Abstract
This study presents a new approach to sensor placement strategy in emitter localisation problems based on time difference of arrival measurements. The method addresses a flexible procedure which is capable of positioning the sensors in constrained environments or non-stationary situations where the positions of the sensors are restricted to certain parts of the space and/or need to be changed repeatedly. This method is sequential and has lower computation burden compared to other methods. The validity of the proposed algorithm is assessed by many different numerical scenarios and the results verify its proper operation. © The Institution of Engineering and Technology 2017
Optimal sensor placement for multi-source AOA localisation with distance-dependent noise model
, Article IET Radar, Sonar and Navigation ; Volume 13, Issue 6 , 2019 , Pages 881-891 ; 17518784 (ISSN) ; Amiri, R ; Behnia, F ; Sharif University of Technology
Institution of Engineering and Technology
2019
Abstract
In this study, the optimal sensor placement problem for multi-source angle of arrival localisation is investigated. The authors adopt the A-optimality criterion, maximising the trace of Fisher information matrix, to determine the optimal sensor-target geometry under distance-dependent Gaussian noise model. A recursive representation of the Cramer-Rao lower bound is derived to recast the sensor placement problem into a sequential method, obtaining the optimal sensor geometries in a step by step manner. Note that the state-of-the-art methods are highly sensitive to the source location changes such that they should be relocated by any later changes in target geometries, which is practically...
Moving target localization in bistatic forward scatter radars: performance study and efficient estimators
, Article IEEE Transactions on Aerospace and Electronic Systems ; Volume 56, Issue 2 , 2020 , Pages 1582-1594 ; Amiri, R ; Behnia, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2020
Abstract
This paper considers the localization of a moving target using a forward scatter radar consisting of a transmitter and an array antenna receiver. A direct positioning method based on maximum likelihood (ML) estimation is proposed and compared with the conventional two-step method in which the primary parameters, including Doppler shift and angle of arrival, should be determined in the first step. Moreover, closed-form expressions for Cramer-Rao lower bound of both methods are derived. The aforementioned methods are comprehensively compared in terms of positioning accuracy and computational complexity. Theoretical performance study, including determining the minimum required observation time...
Optimal sensor placement for multi-source AOA localisation with distance-dependent noise model
, Article IET Radar, Sonar and Navigation ; Volume 13, Issue 6 , 2019 , Pages 881-891 ; 17518784 (ISSN) ; Amiri, R ; Behnia, F ; Sharif University of Technology
Institution of Engineering and Technology
2019
Abstract
In this study, the optimal sensor placement problem for multi-source angle of arrival localisation is investigated. The authors adopt the A-optimality criterion, maximising the trace of Fisher information matrix, to determine the optimal sensor-target geometry under distance-dependent Gaussian noise model. A recursive representation of the Cramer-Rao lower bound is derived to recast the sensor placement problem into a sequential method, obtaining the optimal sensor geometries in a step by step manner. Note that the state-of-the-art methods are highly sensitive to the source location changes such that they should be relocated by any later changes in target geometries, which is practically...
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...
Localization in MISO airborne passive radar through heavy ground clutters
, Article Proceedings of 2015 IEEE East-West Design and Test Symposium, EWDTS 2015, 26 September 2015 through 29 September 2015 ; 2015 ; 9781467377751 (ISBN) ; Amiri, R ; Behnia, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2015
Abstract
The relative velocity between ground surface and receiver platform leads to clutter expansion in the range-doppler surface. The expanded clutters can mask slow moving targets. The passive radar is a low cost and light weight radar with high detection ability, due to its multistatic geometry. In this paper, we employ the MISO passive radar with at least four transmitters of opportunity to constitute an over-determined system of equations. We propose an algorithm to localize moving targets in the presence of clutters. In the first step, the clutters are separated from moving targets and in the second one, the position and velocity of the target are computed by solving the system of equations....
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...
Bounds on compressed voice channel capacity
, Article IWCIT 2014 - Iran Workshop on Communication and Information Theory ; 7-8 May , 2014 , pp. 1-6 ; ISBN: 9781479948772 ; Kazemi, R ; Barazandeh, B ; Behnia, F ; Sharif University of Technology
2014
Abstract
The voice channels present in cellular communication networks provide reliable, widespread and high priority communication mediums. Using these voice channels as a bearer for data transmission allows to deliver high Quality of Service data. But voice channels include vocoders that hinder the data flow by compressing the waveforms prior to transmission. Calculating vocoder channel capacity remains a challenging problem since no analytical model has been proposed for the vocoder channel so far. In this research, simplified models for the vocoder channel are proposed and bounds on vocoder channel capacity are derived based on them. In common cellular networks, the vocoder compression rate is...
Sensor placement in AOA localization of multiple sources in the presence of distance dependent noise
, Article 27th Iranian Conference on Electrical Engineering, ICEE 2019, 30 April 2019 through 2 May 2019 ; 2019 , Pages 1233-1238 ; 9781728115085 (ISBN) ; Hamdollahzadeh, M ; Behnia, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
In this paper, we consider the problem of sensor placement for passive source localization under conditions where there are multiple sources and noise measurement is distance dependent. To this end, first we derive the Cramer-Rao bound for the angle of arrival (AOA) based source localization for distance-dependent noise model and existence of multiple sources. Then, the optimal arrangement of sensors to achieve this bound is obtained
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