A Comprehensive Evaluation of Joint Range and Angle Estimation in Ultra-Wideband Location Systems for Indoors

Fine time resolution enables Ultra-Wideband (UWB) ranging systems to reliably extract the first multipath arrival corresponding to the range between a transmitter and receiver, even when attenuated in strength compared to later arrivals. Bearing systems alone lack any notion of time and in general select the arrival coinciding with the strongest path, which is rarely the first one in non line-of-sight conditions. Complementing UWB ranging systems with bearing capabilities allows indexing the arrivals as a function of both time and angle to isolate the first, providing precision range and angle. In order to gauge the limits of the joint UWB system, we carry out close to 20000 measurements up to 45 m in non line-of-sight conditions in four separate buildings with dominant wall material varying from sheet rock to steel. In addition, we report performance for varying bandwidth and center frequency of the system.