Optimization on TDOA-Based Localization and its Feasibility Study

Heidari, Vahid | 2015

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  1. Type of Document: Ph.D. Dissertation
  2. Language: Farsi
  3. Document No: 47670 (05)
  4. University: Sharif University of Technology
  5. Department: Electrical Engineering
  6. Advisor(s): Haj Sadeghi, Khosrow; Pezeshk, Amir Mansour
  7. Abstract:
  8. In this thesis, the problem of locating a source based on the time difference of arrival (TDOA) has been studied and three different methods have been presented to improve the precision of the positioning. The first method is a solution to the least square error (LSE) by utilizing a convex problem. Generally, the mentioned problem is a non-convex problem; however, it is possible to convert it to a convex one by some relaxation in the constraints. By some justifiable and insightful relaxation, not only we obtain a convex problem, but also the exact solution of the main problem is derived. The second method is using high perturbed TDOA measurements which severely affected the localization. Thus, it seems that no useful information is available in them. However, we utilize only one set of TDOA measurements, even highly perturbed, to propose a line equation passing through the position of the source. The proposed line can be applied as a constraint of the source position. The third method is an approach to reduce the damaging effects of shortcomings in the system of synchronization. We propose an estimator to obtain both the source position and the amount of the undesired biases by utilizing the concept of overdetermined system of linear equations and the maximum likelihood (ML) estimator
  9. Keywords:
  10. Least Squeres Error (LSE) ; Discount ; Synchronisation ; Localization ; Maximum Likelihood Estimation ; Relaxation Time ; Overdetermined Equations System ; Time Difference of Arrival (TDOA)

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