Accurate Indoor Positioning using Multipath Components

Global navigation satellite systems (GNSSs) can deliver very good position estimates under optimum conditions. However, especially in indoor scenarios with severe multipath propagation and blocking of satellites the accuracy loss can be very large. Strategies to mitigate multipath effects on the ranging estimate are in general based on the estimation of the channel impulse response (CIR). These methods have in common, that they determine the multipath in order to remove the influence on the estimate of the line-of-sight (LoS) path. This paper researches multipath aided positioning. Hence, the paper uses additionally the multipath components (MPCs) of the signal for obtaining better positioning performances. Therefore, the novel algorithm treats MPCs as transmitters from virtual transmitter (VT) with a fixed location. To estimate the receiver position and the VT positions at the same time, this paper derives a simultaneous localization and mapping (SLAM) algorithm, where the VTs are interpreted as landmarks. The last part of this paper evaluates the positioning performances of the developed algorithm in a simulated indoor scenario. These evaluations show clearly the advantage of the new algorithm. The simulations show, that also accurate position estimation in non-line-of-sight (NLoS) scenarios is possible. Especially in these scenarios, accurate position estimation with common and advanced position estimation algorithm is impossible. Furthermore, the new algorithm does not rely on any prior information such as the room layout or information collected in a database for fingerprinting.