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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  

    Optimal Sensors Placement for Passive Source Localization Considering NLOS Conditions

    , M.Sc. Thesis Sharif University of Technology Solhi Jouybari, Mohammad (Author) ; Behnia, Fereidoon (Supervisor)
    Abstract
    Passive Location is to obtain the location and velocity of a radio source using a source-generated signal in the environment and extract its parameters, which today have many applications in controlling security activities, tracking people and vehicles, emergency services, radar, Sonar, electronic warfare, and etc. . The location of a source is obtained by using a variety of methods such as received signal strength (RSS), signal angle of arrival (AOA), signal time of arrival (TOA), time difference of arrival (TDOA), and frequency difference of arrival (FDOA) of received signals. Many studies have been done in measuring and extracting data and solving the equations. However, little research... 

    Extract Non-Line-of-Sight state of base stations and error mitigation technique for wireless localization in micro-cell networks

    , Article Computer Communications ; Volume 35, Issue 7 , 2012 , Pages 885-893 ; 01403664 (ISSN) Dehghani, H. L ; Golmohammadi, S ; Shadi, K ; Sharif University of Technology
    2012
    Abstract
    Non Line of Sight (NLOS) propagation is a challenging issue which the performance of network based wireless localization is limited by errors primarily caused by NLOS corruption. NLOS is inherently a dominant source of errors in metropolitan area wireless networks, like cellular one, so in this paper we discuss our proposed algorithm within cellular network terminology. This paper contributes two novel algorithms. The first one is to extract the NLOS state of base station (BS) and the second one is a correction algorithm to enhance the measurements accuracy. Our proposed algorithm discuses a novel localization technique to estimate true mobile terminal (MT) location from a set of possibly... 

    Non-line-of-sight error mitigation technique for wireless localization in micro-cell networks

    , Article 2011 4th IFIP International Conference on New Technologies, Mobility and Security, NTMS 2011 - Proceedings, 7 February 2011 through 10 February 2011, Paris ; 2011 ; 9781424487042 (ISBN) Dehghani, H. L ; Shadi, K ; Golmohammadi, S ; Sharif University of Technology
    2011
    Abstract
    Non Line of Sight (NLOS) propagation is a challenging issue which cause large errors in wireless localization systems. NLOS is especially a dominant source of errors in metropolitan area wireless networks like cellular ones. We discuss our algorithms within cellular network terminology. This paper contributes two novel algorithms. The first algorithm is to extract the NLOS state of base stations and the second one is a correction algorithm to enhance the measurements accuracy. Our introduced algorithms can easily operate with other wireless localization algorithms and reduced NLOS error. These algorithms are proposed for network-based localization because of the amount of calculation  

    NLOS identification in range-based source localization: statistical approach

    , Article IEEE Sensors Journal ; Volume 18, Issue 9 , 1 May , 2018 , Pages 3745-3751 ; 1530437X (ISSN) Abolfathi Momtaz, A ; Behnia, F ; Amiri, R ; Marvasti, F ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2018
    Abstract
    Least squares estimation is a widely-used technique for range-based source localization, which obtains the most probable position of mobile station. These methods cannot provide desirable accuracy in the case with a non line of sight (NLOS) path between mobile station and base stations. To circumvent this drawback, many algorithms have been proposed to identify and mitigate this error; however, they have a large run-time overhead. On the other hand, new positioning systems utilize a large set of base stations, and a practical algorithm should be fast enough to deal with them. In this paper, we propose a novel algorithm based on subspace method to identify and eliminate the NLOS error.... 

    Upper bounds on the ergodic and outage capacities of relay networks using UWB links

    , Article 40th Asilomar Conference on Signals, Systems, and Computers, ACSSC '06, Pacific Grove, CA, 29 October 2006 through 1 November 2006 ; 2006 , Pages 646-650 ; 10586393 (ISSN); 1424407850 (ISBN); 9781424407859 (ISBN) Zeinalpour Yazdi, Z ; Nasiri Kenari, M ; Wehinger, J ; Mecklenbräuker, C. F ; Sharif University of Technology
    2006
    Abstract
    We derive, evaluate, and discuss upper bounds on ergodic and outage capacities for a three-node relay network. The considered relay network has ultra-wideband (UWB) radio channels between the source, destination, and relay nodes. The derived bounds indicate that ergodic and outage capacities of the considered UWB-linked network increase up to 300% when a relay between the source and the destination is used. Furthermore, the bounds indicate that there is an optimum position for the relay node between the source and the destination, where ergodic capacity is maximized. Our numerical results shows that for the non-line-of-sight (NLOS) scenario, with the same signal to noise ratio on all links,... 

    Design of Multi Frequency, Multi Constellation GNSS Receiver

    , M.Sc. Thesis Sharif University of Technology Abolfathi Momtaz, Abbas (Author) ; Behnia, Fereidoon (Supervisor)
    Abstract
    With the advent of new global navigation satellite systems and the technical progress of GPS, some valuable advantages can be achieved by using a combination of data from different constellations. There are some inter system biases between two separate constellation. One has to consider these biases in order to earn better accuracy in a multi constellation receiver. One of the main sources of the error in the position estimation is the random delay of the signal in the ionosphere layer. Recently GPS has released its dual frequency feature on civilian users. Using this feature, receiver will be able to estimate ionospheric delay due to its frequency dependence. The non-line-of-sight path of...