Master of Science in Electrical Engineering (MSEE)
Electrical and Computer Engineering
In this thesis, wireless localization is investigated based on multiple noisy estimates of the time-difference of arrival (TDOA) at each pair of the n >= 4 sensors with different but known locations using WiFi opportunistic signals. Our work is comprehensive and includes channel estimation, symbol detection, TDOA estimation, and location estimation. To mitigate the multipath issue induced by wideband signals, such as WiFi, frequency-division is employed to decompose the wideband RF signal into multiple non-overlapping narrowband signals. To minimize the adverse effects of the clock drift, time-division is proposed to divide the signal into multiple non-overlapping signals in the time domain. In addition, Kalman filtering is proposed, assuming the wide-sense stationary and uncorrelated scattering (WSSUS) channel and the first order auto-regressive (AR) model are used. Because of the multiple TDOA estimates at each pair of the WiFi receiver sensors, an efficient algorithm is developed to estimate the target location. The localization technique developed in this thesis can also be extended to other radio frequency (RF) signals, as shown in our simulation study for out-door localization. The simulation results in our thesis show the effectiveness of the wireless localization, although further work is needed to resolve the nonlinear estimation problem involved in localization based on TDOA estimates.
Document Availability at the Time of Submission
Secure the entire work for patent and/or proprietary purposes for a period of one year. Student has submitted appropriate documentation which states: During this period the copyright owner also agrees not to exercise her/his ownership rights, including public use in works, without prior authorization from LSU. At the end of the one year period, either we or LSU may request an automatic extension for one additional year. At the end of the one year secure period (or its extension, if such is requested), the work will be released for access worldwide.
Kang, Hyundeok, "Wireless Localization in the Absence of GPS" (2015). LSU Master's Theses. 726.