Position information has long been a desired quantity in a host of applications. The advent of the Global Positioning System (GPS) provided reliable and accurate information world wide for outdoor environments. However, many applications are emerging where position information is required and the environment or complexity considerations prohibit the use of GPS (e.g., indoor applications). As a result, areas as diverse as robotics, sensor networks, and ubiquitous computing have seen an increase in research into indoor position location. However, the majority of current work relies on laser, ultrasound, or narrowband RF for positioning. Such techniques are severely limited in harsh environments with significant multipath and/or interference. Unfortunately, many applications (e.g., emergency response, urban troop deployment, disaster relief) must deal with such harsh environments. In this research the investigators investigate an Ultra wideband-based (UWB) position location network approach which is ad hoc in nature and aims to overcome these limitations.
There are significant challenges associated with the development of position location networks for harsh environments. This work addresses four primary unsolved problems: (1) ranging with UWB signals in non-line-of-site environments, (2) signal acquisition of the primary path in dense multipath scenarios, (3) MAC design for UWB-based position location networks and (4) network position determination with a limited number of anchors. The research addressing these challenges uses a mixture of local signal processing methods and collaborative, network-level techniques.
