TOA geo-location for real-time indoor wifi localization system

• Main Author: Cao, Guopeng
• Other Authors: Ng Boon Poh
• Format: Theses and Dissertations
• Language: English
• Published: 2011
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Wireless communication systems
• Online Access: http://hdl.handle.net/10356/43522
• Institution: Nanyang Technological University

Nowadays, indoor localization system based on local-area wireless networks is becoming a hot research topic. Accurate indoor positioning with minimum dedicated infrastructure is required for certain critical applications such as emergency rescue, fire brigades or incident management. This report presents a Time of Arrival (TOA)-based localization system for IEEE 802.11b network. Our approach is based on Round-Trip-time (RTT) measurements using standard IEEE 802.11b link-layer frames. The main goal of this report is to describe a complete positioning process and architecture of a TOA-based WiFi localization method. We also conduct experiments to measure the time difference between sending a data packet and receiving the corresponding immediate acknowledgement to determine the distance between two wireless nodes for localization sensing applications. Meanwhile, the Wireshark software is used to record the time of the packets sending and receiving. It can be seen that the propagation delays correlate closely with the distance, having only a measurement error of a few meters. To overcome the low time resolution of the given hardware timers, some statistical methods are applied, such as mean filter.