Ising Model Formulation Of Outlier Rejection, With Application In Wifi Based Positioning

Multipath interference causes the antenna array of an anchor to estimate several angles of arrival (AoA) for a single user. The resulting ambiguity regarding the line of sight (LoS) component can lead to severe errors in location estimation. This work formulates the problem within an outlier rejection framework: a set of candidate locations are computed by considering all AoAs at all anchors; with the observation that LoS AoA vary less than non-LoS AoA, over several time instances an inlier set can be found that clusters around the true user location. This work then derives an Ising model representation for finding the inlier set and solves the NP-hard problem using the Digital Annealer (DA). Simulations show that this approach improves median localization accuracy by 48.5% when compared to the state-of-the-art in localization methods.