Device-Free Localization of Multiple Humans with Passive RFID and Joint RSSI-Phase Techniques

This work studies device-free localization (DFL) of static humans in a room, which is challenging since lack of mobility cannot offer additional tracking and filtering equations. Contrary to data-driven techniques, no training data is required, but instead, measurements of the room with or without people are only needed, using a minimal number of RFID reader antennas and a large number of passive RFID tags. Two phase-based methods are proposed: one employing group sparsity and RF propagation, and another relying on phase and read rate fluctuations; as a collateral dividend, this work offers a practical method that combines results from different DFL techniques. Numerical results show that the fusion scheme of independent DFL methods, based on signal strength and phase offers improved performance.