AOD/AOA/TOA-based 3D positioning in NLOS multipath environments

Wireless localization has attracted increasing attention from both researchers and engineers. Most of the state-of-the-art localization techniques are designed based on line-of-sight (LOS) radio propagation. The present paper focuses on indoor scenarios which are multipath and rich scattering environments considering non-line-of-sight (NLOS) propagations. Based on the measured angle-of-departure (AOD), angle-of-arrival (AOA), and time-of-arrival (TOA), we propose a three dimensional (3D) least squares (LS) positioning technique assuming a single-bounce reflection in every NLOS propagation path. Furthermore, we derive the Cramer-Rao lower bound (CRLB) for the root mean-square error (RMSE) of the mobile station (MS) position estimate. The system performance is assessed not only based on Monte-Carlo simulations and the analytical CRLB, but also based on real world measurements. It is shown that the proposed technique can accurately estimate the MS position with a root square error of approximately 21 cm in a real laboratory room.