An approach to wireless indoor positioning system

This research project focuses on developing a wireless indoor positioning system that can potentially be commercialized for civil use. Compared to the outdoor positioning systems that are more fully developed with products that produce navigation solutions, the lack of existing stable, robust and precise wireless indoor positioning systems aroused our interest in developing one. Such a system can locate objects or people inside a building and can be extremely useful for users such as malls or hospitals to provide navigation aid or emergency services. Among all the methods available, we chose to use the phase difference calculation method. The signal transmitted from the client side will first be mixed with the crystal oscillator from the server side, and then pass through a notch filter that filters out the signal with higher frequency, and eventually be transmitted back to the receiver from the client side. Since there is a phase difference between the transmitted and the received signal from the client side, we are able to figure out the distance between the client and server and thus provide the location of the client. Our method proved to work with several wire-connected experiments. In order to visualize and extract the phase difference in a wireless environment, we connected two antennas to the network analyzer and analyzed the phase of S21 in ADS (Advanced Design System).U of I OnlyUndergraduate senior thesis not recommended for open acces