Estimation and Detection of Substances Using Wireless Ultra wideband (UWB) radio Propagation Channels

Ultra wideband (UWB) Communications Technology is a new technology especially, for indoor environments, which has emerged in the last twenty years. The Channels Complex Coefficients are measured using a device called a Vector Network Analyzer (VNA). Such characterizations are typically done in a laboratory or an office. Few studies look at the effect of the substances between the transmitter and receiving antennas on the frequency response of the UWB channel. The research question of this thesis to be explored is can we use UWB channel coefficients to detect a variety of different liquid materials and volumes of each. This study provides a low-cost system to accomplish this by applying a data mining technique to the collected frequency traces. The research involves the measurements and analysis of the UWB Radio Propagation Channels in the presence and absence of various substances (liquids and gases) between the transmitting and receiving antennas using LOS (Line of Sight). The substances studied include methane, carbon dioxide (CO2), ocean water and two distinct types of crude oil. This technology allows us to detect the presence of different substances / materials through the UWB radio propagation channels using channel characteristic coefficients to which is applied the analysis algorithm using K-Nearest Neighbour. The hypothesis under study in this thesis is whether we identify these various liquids and gases under controlled laboratory environments in the presence of multipath. The collection of research studies in this thesis produces a proven novel technique to measure different substances in the wireless medium.