Chipless UWB TDR RFID landmark-based positioning using polarimetric filtering

This paper presents a wireless positioning concept based on time domain reflectometry (TDR) chipless radio frequency identification (RFID) landmarks. The concept is intended for vehicle or mobile robot localization in indoor scenarios. Chipless RFID tags are well suited to serve as uniquely recognizable landmarks in industrial or warehouse scenarios due to their unlimited life cycle and robustness. The tag information is read and the tag position is measured with an ultra-wideband frequency modulated continuous wave reader with 7.875 GHz center frequency and 1.25 GHz bandwidth. To cover a sufficiently large localization area, the developed reader and tag allow for a read range of more than 4 m, which is outstanding for chipless TDR RFID. To reduce ranging and identification distortions caused by multipath propagation, we applied a polarimetric filter. The effectiveness of this polarimetric filter and of the positioning capability is verified by laboratory measurements in an indoor environment.