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Research On Localization Algorithms In Wireless Sensor Networks

Posted on:2010-09-19Degree:DoctorType:Dissertation
Country:ChinaCandidate:Y P ZhuFull Text:PDF
GTID:1118330338495718Subject:Signal and Information Processing
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Advances in micro-electro-mechanical system (MEMS) technology, wireless communications and digital electronics have enabled the development of low-cost, low-power, multifunctional sensor nodes that are small in size and communicate untethered in short distances recently.These tiny sensor nodes which consist of sensing, data processing, and communicaiting components, leverage the idea of wireless sensor networks (WSNs) based on collaborative effort of a large number of nodes. WSNs have extensively drawn academic and industrial attention. WSNs have a variety of applications in the aspects of industry, military, and environment. Sensor localization is one of important supporting techniques of WSNs. When sensors'locations are unknown, WSNs cannot play roles in practical applications. Therefore, it is an important part of research of WSNs to develop efficient and expeditious localization methods.The work reported in this dissertation follows active international research directions. Based on the properties of WSNs, e.g., self-organization, low-power consumption, high redundancy, short distance, and flexible network distribution, new localization methods for WSN are proposed in this dissertation, through which the localization accuracy can be improved without changing the sensor configuration of WSNs. In order to increase the localization accuracy, decrease the computational cost, and improve the scalability of localization methods, this dissertation focuses on collaborative localization methods, which are seldom studied currently in China. The proposed localization methods are based on convex optimization. This design strategy is first employed in China. Thus, the proposed methods are of profound significance in both theoretical study and practical application.The dissertation is organized as follows:Firstly, we study various existing localization methods, such as maximum likelihood estimation, Taylor least-squares method, total least-squares method, and newly proposed semi-definite programming (SDP) method. Through algorithmic analysis and simulation experiments, the advantages and disadvantages of these existing methods are pointed out.Secondly, convex optimization is employed to resolve sensor localization problems of WSNs. As an attempt to overcome the disadvantage of the SDP-based localization method, novel methods based on linear programming (LP) and quadratic programming (QP) are proposed in this dissertation. For the localization methods of using distance-angle and pure angle measurements, mathematical derivations, theoretical analysis, and simulation experiments are conducted, respectively. Simulation results illustrate that compared with SDP-based method, the proposed localization methods can effectively reduce the computational cost, improve the localization accuracy, and decrease the dependence on the distribution of anchor nodes.Thirdly, as an attempt to improve the localization accuracy, a minimax optimization strategy is employ to further reduce the worst-case localization error. Simulation results show that the worst-case localization error for each unknown sensor can be effectively reduced, as well as the overall performance of the localization method is unaffected.At last, upon the consideration that GPS cannot be utilized in localization of unmanned aerial vehicle (UAV), a new strategy is proposed to apply sensor localization technique as a complement means in UAV localization. Furthermore, a novel thought of using UAV as a relay station of WSNs is proposed in this dissertation. Some innovative ideas on the diverse development of navigation and positioning system of UAV are also discussed in this dissertation. Some prospective studies regarding the implementation issues are made in this dissertation. All of these are of especial importance.All the localization methods proposed in this dissertation have been verified through simulation experiments on Matlab platform. The corresponding performance analysis is also carried out.
Keywords/Search Tags:Wireless sensor networks, localization, convex optimization, semi-definite programming, linear programming, quadric programming, minimax optimization, unmanned aerial vehicle
PDF Full Text Request
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