NLOS detection algorithms for Ultra-Wideband localization

Non Line of Sight (NLOS) channels are one of the major drawbacks for accurate ranging and localization with Ultra-Wideband (UWB) technology. Whereas several proposals exist to detect these situations, a comprehensive overview, investigation and testing of these methods has to the authors´ knowledge not yet been prepared. This paper tries to fill this gap with a classification of the algorithms proposed of the UWB and mobile phone community. In addition, one novel method based on the signal power variation is suggested. Afterwards, the methods are evaluated regarding their practicability for real UWB localization systems, which excludes some of them from further investigation. For the remaining algorithms thresholds are proposed, which are strived to be as independent of the system and environment as possible. Finally, the NLOS detection algorithms are tested and compared with both an UWB simulation environment and an UWB localization test bed.