UWB TDoA-based Positioning Using a Single Hotspot with Multiple Anchors

In this paper, we address target positioning in scenarios where the reference nodes, denoted as anchors, are not distributed at the perimeter of the area where the target is, but are concentrated in a very small region and target is outside this region. This scenario may be meaningful in smart building applications, where anchor nodes cannot be distributed and cabled in the monitored area. On the other hand, anchors may be installed on a single hotspot to be placed at the center of the environment of interest. In this case, the target has to be localized outside the polytope identified by the anchors. To this end, we investigate Ultra WideBand (UWB)-based target positioning with Time Difference of Arrival (TDoA) processing at the anchors. A comparative analysis between geometric and Particle Swarm Optimization (PSO) algorithms is carried out. Our results show accurate angle of arrival estimation accuracy. Moreover, while PSO guarantees a better performance, in terms of average position estimation error, the 'dispersion' of position estimation (i.e., the standard deviation of the position error) is higher than in the case of geometric algorithms.