Analysis of Kalman Filter-Based Localization for HIMR RFID Systems

Hybrid inertial microwave reflectometry (HIMR) is one of the most promising technologies for achieving the elusive, ultimate goal of wireless localization, i.e., motion-capture grade position tracking at long-range distances. In this paper, we introduce and analyze Kalman filter-based real-time position estimators for HIMR systems. Results from measured data show that the new approach results in a 5 mm RMS tracking error at a range of several meters—a 25% improvement with enhanced robustness over existing position estimators. Moreover, this performance level is shown to be achievable using only RF signals, without inertial data, thereby potentially simplifying RFID-based motion capture system design in many cases. The technique is scalable to ranges of tens- and hundreds-of-meters.