A 5.8 GHz Cooperative Transponder System for Localization and Communication in Traffic Safety Applications

A new cooperative transponder system for traffic safety applications is presented. The prototype system uses three different channels in a frequency range of 5.773 to 5.925 GHz to detect and localize vulnerable road users, infrastructure and other cars equipped with transponders in order to improve traffic safety, even under non-line of sight conditions. Two 10 MHz channels are used for ad-hoc network management, communication and angle of arrival estimation, while one 54 MHz channel is used for round-trip time of flight measurements, combining precise relative localization with data communication between equipped cars and multiple road users or infrastructure transponders. In the current implementation, data communication is carried out by an orthogonal frequency division multiplex link, while the distance measurement utilizes the idea of a secondary radar with pulse compression, using amplitude modulated pseudo noise codes and time division multiple access for multiuser support. This paper describes the system setup as well as an implementation of the prototype hardware and shows the current performance of the system in laboratory and real world measurements.