TOA/AOA/AOD-based 3-D mobile terminal tracking in NLOS multipath environments

Recently several authors have proposed different indoor positioning and tracking algorithms. Most of the proposed indoor positioning and tracking algorithms try to identify and mitigate the errors caused by the non-line-of-sight propagation paths. In this paper, we propose a three-dimensional tracking technique to track a mobile terminal which moves in a non-line-of-sight multipath environment by applying the extended Kalman filter. The proposed tracking technique requires at least one base station and exploits the non-line-of-sight propagations to estimate the three-dimensional trajectory of a mobile terminal by considering the successive angle-of-departure, angle-of-arrival, and time-of-arrival measurements under the assumption of stationary scatterers. Additionally, the position of the scatterers is determined implicitly. It is shown, by simulations, that the proposed three-dimensional tracking technique can estimate the trajectory of a mobile terminal in non-line-of-sight multipath environments very well. In general, the proposed tracking technique improves the position estimates of the mobile terminal compared with tracking made by successive independent position estimates. The improvement in position estimates comes from the exploitation of the correlation between successive measurements which arise from the physical mobility constraints of the mobile terminal.