Radio frequency identification (RFID) has experienced tremendous development in recent decades and has been widely applied into many areas in industry and daily life. The rapid development of microelectronic technology makes RFID tags smaller, cheaper, and more powerful, especially in ultra high frequency (UHF) passive RFID technology. These remarkable technical advances have resulted in more and more supermarkets and libraries, such as Walt-Mart and university libraries, introducing RFID techniques into their traditional systems. Utilizing these existing RFID infrastructure to perform value-added services, such as user behavior analysis and item positioning, becomes a hot research topic, where indoor navigation using UHF passive RFID system is the representational one.

A typical proce...[ Read more ]

Radio frequency identification (RFID) has experienced tremendous development in recent decades and has been widely applied into many areas in industry and daily life. The rapid development of microelectronic technology makes RFID tags smaller, cheaper, and more powerful, especially in ultra high frequency (UHF) passive RFID technology. These remarkable technical advances have resulted in more and more supermarkets and libraries, such as Walt-Mart and university libraries, introducing RFID techniques into their traditional systems. Utilizing these existing RFID infrastructure to perform value-added services, such as user behavior analysis and item positioning, becomes a hot research topic, where indoor navigation using UHF passive RFID system is the representational one.

A typical process of indoor navigation service contains three periods: identifying the user, positioning the user, and navigating the user. In our first work, we propose a user identification mechanism called OpenSesame, which employs the users’ waving patterns to identify the user. The key feature of this work lies in using four fine-grained and statistic features of handwaving to verify users. In our second work, we propose BackPos, a fine-grained backscatter positioning technique using the COTS RFID products with detected phases. Our studies show that the phase is a stable indicator highly related to tag’s position and preserved over frequency or tag orientation, but challenged by its periodicity and tag’s diversity. We attempt to infer the distance differences from phases detected by antennas under triangle constraint. Further, hyperbolic positioning using the distance differences is employed to shrink the tag’s candidate positions until finding out the real one. In our third work, we propose RollCaller to utilize existing indoor objects with attached RFID tags and a reader to navigate users to their destinations, without need of any extra hardware. The key insight is that a person’s movement has an impact on the frequency shift values collected from indoor objects when close to a tag. Such local human-item spatial relation is leveraged to infer the users position and further navigate the user to a destination step by step.