Three Dimensional Positioning with Two GNSS Satellites and DSRC for Vehicles in Urban Canyons

Limited availability of the Global Navigation Satellite System (GNSS) signals in urban canyons is a preventive factor for implementing many position-based systems. Specifically for vehicles, a variety of applications such as Intelligent Transportation Systems (ITS), navigation, and Location-Based Services (LBS) are not properly functional in dense urban areas due to constrained visibility of the GNSS signals. Tackling this problem, a Cooperative Positioning (CP) method is proposed based on the emerging vehicular communication medium, Dedicated Short Range Communication (DSRC). This method is functional with two Global Positioning System (GPS) satellites and infrastructure-vehicle communication using DSRC. A complementary algorithm, based on Doppler shift, is proposed for mitigating the multipath effect which is considerable in urban canyons. The experimental results verify the viability of the proposed method and its higher performance, about 25%, than that of a GPS receiver in an identical situation.