Comparative study of direct position determination with AOA and TOA methods

• Main Author: Varma Ruchika
• Other Authors: Lu Yilong
• Format: Theses and Dissertations
• Language: English
• Published: 2015
• Subjects: DRNTU::Engineering::Electrical and electronic engineering
• Online Access: http://hdl.handle.net/10356/65146
• Institution: Nanyang Technological University

This dissertation presents a study on the performance evaluation of Direct Position Determination (DPD) method of a single emitting source under line-of-sight conditions and confirms its superiority over the conventional localization methods in various test scenarios, proffering the algorithm to be utilized in the real-world applications demanding high positioning accuracy. The traditional localization methods based on Angle of Arrival (AOA) estimation and Time of Arrival (TOA) estimation involve a two-stage process in which the respective angle/time parameter is measured at each base station independently and then the emitter location is determined using triangulation. Hence, both of the methods are considered to be sub-optimal. The DPD technique, however, is an optimized method which uses the same data as that of the above mentioned methods and locates the emitter source using a single search operation. In cases where the noise statistics are unknown, least square method is applicable to DPD. If the noise is Gaussian, maximum likelihood estimation of location represents DPD. It has been proven that DPD eliminates the measurementsources association problem prevailing in AOA/TOA methods and is classified as a centralized positioning approach. This dissertation provides critical discussions on the performance of DPD in distinctive test schemes such as change in system geometry and the array configuration. It also presents the comparison between AOA, TOA and DPD for single source localization under these conditions. The research conducted confirms that DPD significantly overpowers AOA and TOA methods in terms of positioning accuracy at low SNR values. It is also verified that DPD, with suitable system configurations, delivers better indoor as well as outdoor localization establishments and is a potential localization method. Keywords: DPD, Single Emitter Localization, Antenna Array, Maximum Likelihood