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    Optimal sensor placement for source localization in nlos conditions

    , Article 26th Iranian Conference on Electrical Engineering, ICEE 2018, 8 May 2018 through 10 May 2018 ; 2018 , Pages 435-439 ; 9781538649169 (ISBN) Juybari, S. M. S ; Behnia, F ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2018
    Abstract
    The problem of sensor placement for passive source localization under the non-line of sight signal propagation is considered in this paper. To this end, first we derive the Cramer-Rao lower bound for the time of arrival based source localization under non-line of sight conditions. Then, the optimal arrangement of sensors to achieve this lower bound is obtained in the two important cases with all of the receivers being non line of sight ones in the first case and a combination of line of sight and non-line of sight receivers in the 2nd case. © 2018 IEEE  

    Positioning of geostationary satellite by radio interferometry

    , Article IEEE Transactions on Aerospace and Electronic Systems ; Volume 55, Issue 2 , 2019 , Pages 903-917 ; 00189251 (ISSN) Sadeghi, M ; Behnia, F ; Haghshenas, H ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2019
    Abstract
    There are several perturbations that force the satellite orbit to deviate from the elliptical form. To cope with these perturbations, station keeping is applied. For accurate station keeping, determination of the true satellite orbit is necessary. Radio interferometry is one of the techniques used for determining azimuth and elevation look angles of a satellite. In this paper, we introduce three structures based on interferometry for determining the view angles of satellites. The estimated angles are combined with range measurement for orbital positioning of geostationary (GEO) satellites. In the proposed interferometry structures, to acquire the required angular accuracy, the distance... 

    Positioning of geostationary satellite by Radio Interferometry

    , Article IEEE Transactions on Aerospace and Electronic Systems ; 2018 ; 00189251 (ISSN) Sadeghi, M ; Behnia, F ; Haghshenas, H ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2018
    Abstract
    There are several perturbations that force the satellite orbit to deviate from the elliptical form. To cope with these perturbations, station keeping is applied. For accurate station keeping, determination of the true satellite orbit is necessary. Radio interferometry is one of the techniques used for determining azimuth and elevation look angles of a satellite. In this paper we introduce three structures based on interferometry for determining the view angles of satellites .The estimated angles are combined with range measurement for orbital positioning of geostationary (GEO) satellites. In the proposed interferometry structures, to acquire the required angular accuracy, the distance... 

    Compressed sensing block MAP-LMS adaptive filter for sparse channel estimation and a Bayesian Cramer-Rao bound

    , Article Machine Learning for Signal Processing XIX - Proceedings of the 2009 IEEE Signal Processing Society Workshop, MLSP 2009, 2 September 2009 through 4 September 2009 ; 2009 ; 9781424449484 (ISBN) Zayyani, H ; Babaie Zadeh, M ; Jutten, C ; Sharif University of Technology
    Abstract
    This paper suggests to use a Block MAP-LMS (BMAP-LMS) adaptive filter instead of an Adaptive Filter called MAP-LMS for estimating the sparse channels. Moreover to faster convergence than MAP-LMS, this block-based adaptive filter enables us to use a compressed sensing version of it which exploits the sparsity of the channel outputs to reduce the sampling rate of the received signal and to alleviate the complexity of the BMAP-LMS. Our simulations show that our proposed algorithm has faster convergence and less final MSE than MAP-LMS, while it is more complex than MAP-LMS. Moreover, some lower bounds for sparse channel estimation is discussed. Specially, a Cramer-Rao bound and a Bayesian... 

    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) Hamdollahzadeh, M ; 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  

    Robust relay beamforming against jamming attack

    , Article IEEE Communications Letters ; Volume 22, Issue 2 , February , 2018 , Pages 312-315 ; 10897798 (ISSN) Maleki Sadr, M. A ; Ahmadian Attari, M ; Amiri, R ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2018
    Abstract
    In this letter, we surpass the jamming effect and also estimate the jamming channel state information by using the Kalman filtering approach. Furthermore, we design a closed-form beamforming weight for maximizing the achievable rate subject to the condition that the total relays power transmission would be below a predefined threshold level, which is formulated as a quadratically constrained quadratic program. Simulation results show the efficient performance of the proposed method for different destruction powers of the jammer by achieving the Cramér-Rao lower bound. © 1997-2012 IEEE  

    Antenna and pulse selection for colocated MIMO radar

    , Article 51st Asilomar Conference on Signals, Systems and Computers, ACSSC 2017, 29 October 2017 through 1 November 2017 ; Volume 2017-October , 2018 , Pages 563-567 ; 9781538618233 (ISBN) Tohidi, E ; Behroozi, H ; Leus, G ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2018
    Abstract
    Multiple input multiple output (MIMO) radar is known for its superiority over conventional radar due to its antenna and waveform diversity. However, the increased hardware cost (due to multiple transmitters and receivers), power consumption (due to multiple transmitters and pulses), and computational complexity (due to numerous pulses) form the drawbacks of MIMO radar. On one hand, a higher estimation accuracy is required, but on the other hand, a lower number of active antennas/pulses is desirable. Therefore, in this paper, by proposing a convex optimization approach for the general case of transmitter-receiver-pulse selection, we will minimize the total number of active antennas/pulses in... 

    Reduction of doppler estimation error by multi-frequency transmission

    , Article IET International Radar Conference 2009, Guilin, 20 April 2009 through 22 April 2009 ; Issue 551 CP , 2009 ; 9781849190107 (ISBN) Sebt, M. A ; Sheikhi, A ; Nayebi, M. M ; Sharif University of Technology
    2009
    Abstract
    In this paper, after introduction of symmetric multi- frequency signal, it will be presented how to estimate Doppler frequency from estimated frequency tones of returned echo. After that, three methods of Pisarenko, Prony and MUSIC for frequency estimation will be introduced, and then these methods are applied to estimate tone frequencies of a multi-carrier signal. It will be shown that estimation of Doppler frequency by multi-frequency signal transmission leads to less rms error than single-frequency signal, in the condition of equal SNR. Infact it will be suggested that distribution of the power of signal in spectrum instead of adding up all the power in one point, leads to less Doppler... 

    Closed-form positioning in MIMO radars with antenna location uncertainties

    , Article IET Radar, Sonar and Navigation ; Volume 13, Issue 9 , 2019 , Pages 1568-1579 ; 17518784 (ISSN) Amiri, R ; Behnia, F ; Zamani, H ; Sharif University of Technology
    Institution of Engineering and Technology  2019
    Abstract
    In this study, the authors propose an algorithm to reduce the effect of antenna location uncertainty for locating moving targets in multiple-input multiple-output (MIMO) radar systems. The proposed method is a closed-form solution which employs the measurements of multiple independent targets to alleviate the antenna location uncertainties. The authors establish a pseudo-linear set of equations by using the range and the range-rate auxiliary parameters, which allows the problem to be solved using a two-stage weighted least squares estimator. The proposed method is shown analytically and confirmed by simulations to attain the Cramer-Rao lower bound under small error conditions. The... 

    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) Solhi Juybari, S. M ; 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  

    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) Hamdollahzadeh, M ; 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... 

    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) Hamdollahzadeh, M ; 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... 

    A high-performance guidance filter scheme with exact dynamic modeling of a pitch-yaw gimballed seeker mechanism

    , Article Mechanical Systems and Signal Processing ; Volume 144 , 2020 Ahi, B ; Haeri, M ; Sharif University of Technology
    Academic Press  2020
    Abstract
    This paper is concerned with the problem of guidance filter design for a homing air defense missile using measurements of an on-board pitch-yaw gimballed seeker mechanism. This problem possess a highly nonlinear dynamic which is influenced by various error sources such as seeker's stabilization loop torque disturbances originated from pursuer's accelerations and angular velocities, significant channel couplings, time-delayed and noisy measurements of optical sensor besides the unknown target maneuvers. To handle the inherent nonlinearity of problem a wide variety of assumptions are made in literature to derive simplified engagement kinematics. In present work, performance degradations which... 

    On the cramer-rao bound for estimating the mixing matrix in noisy sparse component analysis

    , Article IEEE Signal Processing Letters ; Volume 15 , 2008 , Pages 609-612 ; 10709908 (ISSN) Zayyani, H ; Babaie Zadeh, M ; Haddadi, F ; Jutten, C ; Sharif University of Technology
    2008
    Abstract
    In this letter, we address the theoretical limitations in estimating the mixing matrix in noisy sparse component analysis (SCA) for the two-sensor case. We obtain the Cramer-Rao lower bound (CRLB) error estimation of the mixing matrix. Using the Bernouli-Gaussian (BG) sparse distribution, and some simple assumptions, an approximation of the Fisher information matrix (FIM) is calculated. Moreover, this CRLB is compared to some of the main methods of mixing matrix estimation in the literature. © 2008 IEEE  

    On molecular flow velocity meters

    , Article IEEE Transactions on Molecular, Biological, and Multi-Scale Communications ; Volume 7, Issue 4 , 2021 , Pages 224-238 ; 23327804 (ISSN) Farahnak Ghazani, M ; Mirmohseni, M ; Nasiri Kenari, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2021
    Abstract
    Flow velocity is an important characteristic of the fluidic mediums. In this article, we introduce a molecular based flow velocity meter consisting of a molecule releasing node and a receiver that counts these molecules. We consider both flow velocity detection and estimation problems, which are employed in different applications. For the flow velocity detection, we obtain the maximum a posteriori (MAP) decision rule. To analyze the performance of the proposed flow velocity detector, we obtain the error probability, its Gaussian approximation and Chernoff information (CI) upper bound, and investigate the optimum and sub-optimum sampling times accordingly. We show that, for binary hypothesis,... 

    Well-conditioned sensor placement for range-only localization

    , Article 2011 4th IFIP International Conference on New Technologies, Mobility and Security, NTMS 2011 - Proceedings, 7 February 2011 through 10 February 2011 ; February , 2011 , Page(s): 1 - 5 ; ISSN : 21574952 ; 9781424487042 (ISBN) Shadi, K ; Dehghani, H. L ; Gholampour, I ; Sharif University of Technology
    Abstract
    This paper addresses the optimality of Network topology for localization purposes when measurements are range-only. Localization procedures based on TOA and TDOA range measurements are considered in this paper. As of now, the optimal placement of fixed terminals to locate mobile terminals has been studied based on Cramer-Rao Lower Bound (CRLB). CRLB is a universal bound on the variance of a general unbiased estimator and therefore is not dependent to the estimator and methods of localization. Here we introduce another algorithm dependent criterion, based on perturbation theory of linear equations. Different optimal topologies are presented using the new criterion. These optimal topologies,... 

    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) Zamani, H ; Amiri, R ; Behnia, F ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc 
    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  

    Target direct position determination in 2D CW forward scatter radar

    , Article Proceedings International Radar Symposium, 10 May 2016 through 12 May 2016 ; Volume 2016-June , 2016 ; 21555753 (ISSN) ; 9781509025183 (ISBN) Hamdollahzadeh, M ; Adelipour, S ; Behnia, F ; Nayebi, M. M ; Sharif University of Technology
    IEEE Computer Society  2016
    Abstract
    This paper proposes an algebraic solution for the position and velocity of a moving target in forward scatter radar based on a single step direct position determination method. Unlike the conventional two-step method, this direct technique does not require the joint estimation of the Doppler frequency and the angle of arrival, initialization step, convergence considerations and linearization approximations  

    Robust relay beamforming against jamming attack

    , Article IEEE Communications Letters ; 2017 ; 10897798 (ISSN) Maleki Sadr, M. A ; Ahmadian Attari, M ; Amiri, R ; Sharif University of Technology
    Abstract
    In this letter, we surpass the jamming effect and also estimate the jamming channel state information by using Kalman filtering (KF) approach. Furthermore, we design a closed-form beamforming weight for maximizing the achievable rate subject to the condition that the total relays power transmission would be below a predefined threshold level, which is formulated as a Quadratically Constrained Quadratic Program (QCQP). Simulation results show efficient performance of the proposed method for different destruction powers of jammer by achieving the Cramer Rao Lower Bound (CRLB). IEEE  

    Efficient 3-D positioning using time-delay and AOA measurements in MIMO radar systems

    , Article IEEE Communications Letters ; 2017 ; 10897798 (ISSN) Amiri, R ; Behnia, F ; Zamani, H ; Sharif University of Technology
    Abstract
    This letter investigates the problem of threedimensional (3-D) target localization in multiple-input multipleoutput (MIMO) radars with distributed antennas, using hybrid timedelay (TD) and angle of arrival (AOA) measurements. We propose a closed-form positioning method based on weighted least squares (WLS) estimation. The proposed estimator is shown theoretically to achieve the Cramer-Rao lower bound (CRLB) under mild noise conditions. Numerical simulations also verify the theoretical developments. IEEE