Anchorless Indoor Localization and Tracking in Real-Time at 2.45 GHz

This paper introduces a custom portable RFID (Radio-Frequency IDentification) reader, performing bi-dimensional beam-steering in real-time by means of the radar monopulse principle. The system is able to simultaneously track the angular position of multiple tagged entities (objects or people), static or dynamic, with respect to the azimuth and elevation planes. Furthermore, a simple signal processing algorithm, running on board of the reader, is used to derive an estimate of the tags-to-reader distances, thus allowing a 3D-position assessment of the tracked entities. This portable device can be exploited in Ambient Assisted Living (AAL) applications to perform a tri-dimensional scanning of a room and detect potential falls of the monitored people. The scanning data, collected during the device tracking operations, can further provide various feedbacks regarding the tagged people behaviour; for this purpose, a procedure to remotely control the whole system is introduced making use of a Raspberry Pi 3B directly connected to the reader output and wirelessly communicating with the environment monitoring platform. In this way, a seamless link of the portable reader to a software architecture, able to control several devices and processes at the same time, is obtained.