Vehicle Positioning Using Direction of Arrivals of Collaborative Road Side Units and Spatial Geometry

Lane-level autonomous driving relies on high-accuracy vehicle positioning. Among different vehicle positioning approaches, direction of arrival (DOA) based solutions are competitive as they avoid measuring delay information. However, a large distance between the vehicle and road side unit (RSU) compared to the antenna array aperture limits the positioning performance of the existing methods. To address this issue, in this paper, we propose an iterative positioning method using two collaborative RSUs and the spatial geometry, where the DOAs and the positions of vehicles are iteratively estimated. Numerical simulations demonstrate that the proposed method can achieve a positioning performance of millimeter-grade, improving the positioning performance by one to two orders of magnitude, compared to state-of-the-art methods.