Issues on the design of vehicular node positioning based on Doppler-shifted frequency measurement on highway

摘要

Positioning plays a central role in location-based services. In designing such a method of highway applications, it is of paramount importance to provide a quick and precise positioning service. Such design considerations can help reduce the probability of accidents and other traffic troubles. This paper presents a novel and practical vehicular node positioning method which can achieve a higher accuracy, more quickness and more reliability than the existing global-positioning-system-based positioning solutions by making use of doppler-shifted frequency measurements taken by vehicular node itself. This positioning method uses infrastructure nodes which are placed on the roadside every several kilometers as radiation sources to estimate the relative distance and correlative angle of the vehicular node to the infrastructure node instantaneously. Through coordinate conversion, we get the absolute coordinates of vehicular node based on known absolute coordinates of infrastructure node. We also analyze the maximum distance of neighbor infrastructure nodes in order to ensure a high accuracy. In addition, simulation results demonstrate that the performance of our method with extended Kalman filtering (EKF) is superior to the method without EKF and DGPS.