Short-range indoor localization using a hybrid doppler-UWB system

This paper presents a novel hybrid indoor localization solution that combines a wearable K-band trajectory-tracking Doppler radar with an ultra-wideband (UWB) positioning system. A K-band Doppler radar aided with a three-axis digital gyroscope is used to capture the Doppler frequency and the change in the heading direction, thus constantly tracking the trajectory by integrating speed into position change. In order to remove the error accumulated during the integration process, UWB positioning is adopted in a fixed region. Every time a subject walks into the region that is reliably monitored by the UWB positioning system, the location of the subject and the heading direction are calibrated by the UWB measurement result. Details of the tracking theory is presented. Experiments were carried out to demonstrate the advantage of the proposed Doppler-UWB system for short-range indoor localization.