TDOA/AOD/AOA localization in NLOS environments

In this paper we present a novel localization algorithm for use in non-line-of-sight environments. We use the single bounce scattering model to model the non-line-of-sight propagations and estimate the position of a mobile station when the observations are the time-difference-of-arrival, the angle-of-departure, and the angle-of-arrival. The proposed algorithm uses the geometry of the radio propagation paths to estimate the position of the mobile station. An iterative localization algorithm based on the linearization of the observation function using a first order Taylor series is also discussed. The lower bound of the variance of an unbiased mobile station position estimator is determined using the Cramer-Rao lower bound. The performance of the proposed algorithm is analyzed using measurements from a real world indoor localization scenario and using Monte-Carlo simulations. It is shown that the proposed algorithms yield a satisfactory performance.