Optimized tracking for cooperative sensor systems in multipath environments

[摘要] In a cooperative sensor system for pedestrian protection, a pedestrian andother road users exchange data by means of radio frequency communication. Inthe proposed system, the pedestrian carries a transponder which isinterrogated by a vehicle and sends an anonymous identification (ID)sequence. By decoding the ID, the interrogation unit in the vehicle detectsthe presence of the transponder. Evaluating the incident wave of thetransponder's answer, a localisation is possible.

In the proposed localization system, the measurement results can bedistorted by multipath propagation. Multipath errors result if signals ofthe same transponder arrive simultaneously at the receiver unit fromdifferent directions. In this case, erroneous distances and angles aremeasured. Because the signals arriving from different directions contain thesame transponder ID, they can be assigned to their origin. One of thechallenges in post-processing for signal improvement is enhancing theselection of the correct position information by making assumptions aboutthe pedestrian's movement and by knowing the vehicle's current drivingparameters. Additionally, information contained in multipath signals is usedto form a better estimate for the true position of the transponder. Toovercome the problems related to multipath propagation effects, a method isproposed that estimates the origin of a multipath signal and maps thedistorted position information back to the true position. A fusion oftracked direct positions and mapped multipath signals leads to animprovement in positioning accuracy.

[学科分类] 电子、光学、磁材料