Title page for etd-0819111-142037


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URN etd-0819111-142037
Author Ting-Wei Liu
Author's Email Address m983010016@student.nsysu.edu.tw
Statistics This thesis had been viewed 5566 times. Download 1035 times.
Department Electrical Engineering
Year 2010
Semester 2
Degree Master
Type of Document
Language zh-TW.Big5 Chinese
Title Wireless Location with Inertial Assisted NLOS Mitigation in UWB
Date of Defense 2011-07-15
Page Count 79
Keyword
  • location and tracking
  • ultra-wideband
  • non-line of sight
  • Kalman filtering
  • Abstract The thesis is mainly focused on a hybrid location system, which processes wireless and inertial measurements by extended Kalman filtering. Inertial location system is usually used with Dead-Reckoning method, which calculates the present location and heading direction from a previous known state by using measurements of accelerometer and gyroscope, which have immunity from the environment. The system estimates the position by integrates the measurements of sensors, resulting in high accuracy during a short period. However, the unreliability grows with time due to the bias effect on sensors. By combining the wireless location and inertial system, the uncertainty of estimation can be reduced. In wireless communications, the locations of base stations and the times of signal arrival can be used in locating a mobile station. However, signal propagation could be blocked by objects. The non-line of sight (NLOS) effects cause arrival delay and is usually modeled as exponential distributions. Previously, the improved biased Kalman filters were designed to mitigate the NLOS effect in base station measurements. The system design has difficulty in accommodating inertial measurements. The inertial has immunity to the environment. The property is of help in the NLOS mitigation. Therefore, we propose a hybrid location system that integrating the wireless and inertial measurements by using a hybrid biased extended Kalman filter at the stage of positioning. The system provides better prediction with the assistance of enviroment-free inertial measurements. The NLOS mitigation with prediction feedback scheme results in better mitigation performance. Simulations of different situations have been conducted based on parameters in the IEEE 802.15.3a ultra-wideband environment. The performance differences between the proposed method and other approaches show that inertial assisted system effectively reduces the NLOS effects. Also, the proposed hybrid location system has more efficient mitigation performance and better tracking results.
    Advisory Committee
  • Jiann-Der Lee - chair
  • Hsin-Hsyong Yang - co-chair
  • Miin-Jong Hao - co-chair
  • Chin-Der Wann - advisor
  • Tsang-Ling Sheu - advisor
  • Files
  • etd-0819111-142037.pdf
  • Indicate in-campus at 2 year and off-campus access at 2 year.
    Date of Submission 2011-08-19

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