Active radar — A cooperative approach using multicarrier communication

Vehicular safety systems for collisions or sensing rapid changes in traffic typically use two methods to communicate and disseminate traffic hazards. Many current systems use RADAR systems that transmit a radio wave and sense the reflective waves for angle-of-arrival or time-of-arrival information. Several proposed systems use vehicular networks to disseminate information about braking, emergencies or road conditions; when coupled with accelerometer or GPS information, these radio systems may also offer information on speed, traffic density or distance. In-vehicle RADAR systems are relatively expensive; vehicular radio based systems are less expensive. In this paper, we present a cooperative technology that combines these two techniques, seeking to adopt characteristics of both systems by employing a software defined radio for “cooperative RADAR” and vehicular networking. Our method uses multicarrier wireless communication to detect and disseminate. Using precise timing and synchronization, we can detect the distance of each of the vehicles, their current velocity and current acceleration or deceleration conditions. Using simultaneous, multi-party acknowledgments, we can rapidly disseminate or determine information about a number of vehicles in an efficient manner.