Impact of NLOS identification on UWB-based localization systems (original) (raw)

When considering localization systems, one of the most commonly employed reference parameters is the so-called two-way ranging. To obtain this parameter, technologies such as ultra-wideband (UWB) exploit the signal propagation time between two devices: a target and an anchor. However, this parameter is not immune to propagation phenomena such as shadowing, reflections, and diffractions frequently found in indoor environments, leading to a loss of line-of-sight (LOS) conditions between the target and the anchor (i.e., non-line-of-sight (NLOS) conditions), hence degrading the ranging estimations and, consequently, the performance of the algorithms used for the localization. This work studies how the prior knowledge about LOS and NLOS conditions allows for improving considerably the final position estimations. Results based on UWB measurements are considered to evaluate the performance of different positioning algorithms with and without this prior information.