A Channel Capacity Perspective on Cooperative Positioning Algorithms for VANET

Dedicated Short Range Communication (DSRC) technology protocols form a platform for vehicle to vehicle communications. This communication platform will enable Vehicular Adhoc NETworks (VANTEs) through which many Intelligent Transport Systems applications including cooperative positioning of vehicles become possible. Cooperative positioning integrates the on board GPS information of vehicles in one-hop neighbourhood and the measurements of inter-vehicle distances (dissimilarities) that are measured by means independent from GPS. The performance of cooperative positioning can be characterized by Cramar Rao Lower Bound (CRLB) analysis. However, the communication constraints, resulting from the adhoc nature of communication in vehicular networks and packet collisions, affect the calculation of the CRLB; since the number of active one-hop neighbours that each vehicle detects, depending on the network density, can effectively be lower than the real number of one-hop neighbours. Simulating the packet delivery failure rate for a cooperative positioning communication protocol under various network conditions, the CRLB is calculated. It is shown that CRLB increases, on average, up to one meter for dense traffic conditions.