Development of an RF positioning system

• Main Author: Rege, Laukik Jayesh
• Other Authors: Tay, Wee Peng
• Format: Thesis-Master by Coursework
• Language: English
• Published: Nanyang Technological University 2020
• Subjects: Engineering::Electrical and electronic engineering::Antennas, wave guides, microwaves, radar, radio
• Online Access: https://hdl.handle.net/10356/140557
• Institution: Nanyang Technological University

GNSS technology is used in most electronic gadgets and automobiles for positioning and navigation. Ironically, GNSS positioning becomes unreliable in urban canyons, i.e., places where there is a lot of urban infrastructure. This is due to the GNSS signal being obstructed and reflected by objects like tall buildings. Similarly, GNSS does not work accurately in indoor environments like tunnels, parking garages etc. The aim of this dissertation is to develop a system which uses RF based wireless communication for positioning and navigation in the aforementioned GNSS deprived environments. A multi-device ranging algorithm was developed in this dissertation which uses a network of SX1280 transceivers to locate a target. Localization is performed via relative ranging measurements between the various nodes. Due to its noise resilience in both LOS and NLOS environments, LoRa modulation was used to develop the system. The system works in the 2.4 GHz ISM band and was found to be accurate to 0.27m when operating at distances in the range of 0 to 20m in partially NLOS environments. The system was also able to measure the position of a mobile target thus emulating its performance in a VANET cluster. A Kalman filter was also designed and tuned to refine the system measurements and plot the trajectory of the mobile target. The accuracy of the system has scope for improvements via sensor fusion and the efficiency of the system in long range field trials remains to be tested. However, with its current accuracy the system shows great promise in applications involving Intelligent Transport Systems in GNSS deprived settings.