Performance Boundaries for Cooperative Positioning in VANETs

The concept of Cooperative Positioning (CP) has emerged recently to improve the quality of positioning, provided by Global Navigation Satellite System (GNSS), in terms of accuracy and availability. This is necessary to meet the requirements of the vehicular position-based applications such as collision avoidance, which cannot rely only on GNSS performance. CP systems are based on fusing data from different sources, including GNSS, for positioning quality improvement. A typical class of CP is based on the GNSS-based position estimates and distances between the participating vehicles. Inter-vehicle ranging and GNSS errors are limiting factors for achievable performance using CP systems. Inter-vehicle range-rate is also a potential observable for CP systems. In this article, the performance boundaries for range-based and range-rate-based CP systems are investigated. The limits on the achievable performance with different topologies and observations are investigated. Also, the required bandwidth is considered for evaluating the performance of the discussed CP structures.