A Novel Approach based on UWB Beamforming for Indoor Positioning in None-Line-of-Sight Environments

Accurate wireless indoor positioning in non line-of-sight (NLoS) environments is an open research topic due to interfering dense multipath propagation. The key challenge is to reliably detect the direct path (DP) from the transmitter to the receiver so as to enable accurate positioning calculations. In our contribution a novel approach called ”BeamLoc” has been introduced to perform this task. Spatial information is assigned to the transmitted radio signal such that the DP can be easier detected through a unique spatial signature. In this way, not only interfering reflections can be mitigated, but also the DP can be principally captured even if it is attenuated by an object to some extent. BeamLoc relies on combining Ultra-Wideband (UWB) technology with multiple antennas enabling UWB beamforming, which shows several beneficial properties for positioning. Among all other wireless techniques based on EM waves only UWB allows sufficient resolution in centimeter range due to its enormous bandwidth, Besides, UWB beamforming does not suffer from ambiguities (so-called grating lobes) and therefore enables narrowing the main lobe only by widening the antenna separation [2]. Moreover, UWB beamforming doubles the array gain compared to narrowband solutions and therefore halves the required number of antennas [2]. The aim of this contribution is to introduce the BeamLoc approach and to give preliminary results. After a brief introduction and some basic definitions (sections 1 and 2), multipath and NLoS are discussed in the succeeding two sections. Section 5 demonstrates the principles of BeamLoc and section 6 presents preliminary simulation results. Finally, conclusions and future work are conducted in section 7.