TDOA Positioning Based on Factor Graphs

In this paper, we introduce a factor graph based positioning algorithm in wireless cellular networks using time difference of arrival (TDoA) measurements provided by the base stations. The localization process of the mobile station results in a nonlinear estimation problem which cannot be solved analytically. The well-known iterative Gauss-Newton based method as standard solution fails to converge for certain geometric constellations and bad initial values, and thus, it is not suitable for a general processing in cellular networks. Hence, we propose a TDoA positioning algorithm in the factor graphs framework. We show that this approach achieves very accurate positioning estimates by moderate computational complexity