SBIR-STTR Award

Geolocation capability is a critical component of wireless systems for public safety, military, and homeland security. Traditional geolocation systems based on GPS and narrowband modulations work well in areas where a direct line of sight (DLOS) path from multiple sources exist. However, these systems become unreliabile for indoor and urban environments that are characterized by low signal level and severe multipath conditions. This inhibits the ability to accurately detect the time of arrival (TOA) of the DLOS path between transceivers. For TOA measurements, an error in the detection of the DLOS path results in error of the position estimate. These position errors prevent traditional geolocation systems from achieving the location accuracy and system reliability required for military and homeland security applications. Innovative Wireless Technologies (IWT) is proposing an ultra-wideband (UWB) system. The project will combine IWT’s existing knowledge in ad-hoc UWB communications networks and hardware prototyping with industry leading research in indoor positioning to develop innovative geolocation algorithms that take advantage of the multipath-resistant characteristics of pulse-based UWB. System requirements and architecture will be evaluated and innovative geolocation algorithms developed. Tradeoffs between the number of nodes in a network and location accuracy will be determined through propagation channel measurement and characterization.

Benefits:
Improved geolocation capability will benefit many commercial, public safety, and military applications. There are countless commercial applications, including real-time tracking of critical assets, locating children who are away from visual supervision, and monitoring elderly nursing home residents. However, Innovative Wireless Technologies (IWT) will initially focus on the public safety and military applications which include improved situational awareness, identification of friendly forces, and location of hazardous materials such as chemical, biological, and radioactive agents. The development of improved geolocation technology using ultra-wideband (UWB) will complement multiple research and development projects at IWT, expediting the delivery of IWT UWB network products to the market.

Keywords:
UWB, ultra-wideband, indoor, geolocation, positioning, ad-hoc, sensor network

Geolocation in indoor and urban areas is an essential emerging technology to enhance situational/positional awareness capabilities of U.S. soldiers. Maintaining situational awareness in indoor and urban environments is difficult because buildings, walls and other obstacles obstruct RF propagation. Thus the key parameter for geolocation, the direct path propagation signal, is harder to detect. The technical challenge is to develop geolocation algorithms that overcome the direct path obstructions and integrate them into a communication network that is easily deployed, low cost, and collaboratively provides accurate location information. In Phase I, Innovative Wireless Technologies (IWT) proved that a ultra wideband (UWB) geolocation network can provide location accuracy of 1 meter for outdoor to indoor conditions. IWT's innovative UWB ranging and positioning solution is based on multi-band orthogonal frequency division multiplexing (MB-OFDM) which has inherent advantages over pulse-based UWB systems. A key advantage is spectral flexibility which allows individual carriers and frequency bands to be avoided, thereby enhancing the anti-jam performance of the system. In Phase II, IWT will build upon related UWB ad-hoc network projects to implement and demonstrate the performance of the geolocation algorithms. Key position and ranging accuracy parameters will be demonstrated in a mobile environment.

Keywords:
Positioning, Geolocation, Ultra-Wideband, Ad Hoc Network, Mb-Ofdm Uwb, Wireless Communications, Ranging