Cooperative Positioning for Vehicular Networks

Cooperative Positioning (CP) is a technique for localizing some nodes in a wireless sensor network based on communication among the nodes and inter-node distance estimation. In the process of CP, taking advantage of some nodes with known position, anchors, is possible.

CP has been considered in the vehicular environment as an innovative solution for tackling the shortcomings of satellite-based positioning, GNSS. Figure 1 depicts the different situations in which CP can be helpful for positioning and/or positioning enhancement through communication among the vehicles and Road Side Units (RSU) . In situation (a), GNSS-based positioning is possible due to visibility of four satellites. In this situation CP can be used for positioning accuracy enhancement. In situation (b), one of the vehicles does not have visible GNSS Global navigation satellite system satellite but the other one has. CP might be used for position estimation of the first vehicle. In situations (c) and (d), none of the vehicles does not have enough GNSS satellites for positioning. CP might be used for positioning of the vehicles. For simplicity, this figure is depicted with two vehicles and one reference anchor. However, the methods and algorithms for CP may rely on more quantities of vehicles and anchors.

Figure 1- Different situations that CP may be helpful for vehicular networks.