An Approach to Positioning Road-Users in a Telematics Network

In this invited paper, we discuss positioning of road-users in a traffic environment. Once accurate and reliable position information can be made available, many interesting and innovative telematics applications may be realized. Some of the problems facing radio-frequency (RF) based positioning systems today include blocked RF channels and multipath propagation, complicating distance estimation between network members and between network members and the infrastructure. In this work, we propose a novel estimator of range operating on an ultra-wideband (UWB) physical layer. This distance estimator has been designed specifically with a novel type of positioning algorithm in mind, based on the method of projections onto convex sets. Also, we investigate the feasibility of positioning users that are not members of the telematics network based on arbitrary transmitted RF signals. Numerical simulations, using channel models recently adopted by the IEEE 802.15.4a working group, confirm the robustness and accuracy of the proposed approach in the presence of both non-line-of-sight (NLOS) channels, and severe multipath propagation