Direct Positioning in Single-Channel UHF-RFID Systems with Particle Filter-Based Algorithms

This contribution presents a direct positioning algorithm for the movement reconstruction of objects tagged with passive Ultra High Frequency (UHF) Radio Frequency Identification (RFID) tags in postprocessing. We propose a signal model with the assumption of the movement trajectory being separable in piecewise linear parts with constant velocity in the x-y plane. The reconstruction algorithm consists of a Sequential Importance Resampling (SIR) particle filter using a switched antenna system of 14 antennas in a laboratory room. The estimator reaches the Cramer-Rao lower bound (CRLB) under optimal conditions and provides a Root Mean Squared Error (RMSE) of less than 0.3 m for real-world measurement data.