Multiuser detection for transmit-only active RFID

• Main Author: Hoffmann, Dana
• Language: English
• Published: University of British Columbia 2012
• Online Access: http://hdl.handle.net/2429/39892

One of the biggest challenges in Radio Frequency Identification (RFID) systems is mitigating tag collisions. Most systems tackle this problem using Medium Access Control layer solutions. Unfortunately, these solutions are not applicable to systems with transmit-only tags, since the tags cannot detect collisions. This thesis introduces a novel reader design that employs multiuser detection techniques to jointly detect data from colliding packets in such systems. We propose a physical layer solution that exploits signal structure to mitigate tag collisions. Since the RFID tags generate their own clock using inexpensive hardware, this framework poses some unique challenges. We present methods for collision detection, synchronization, and channel estimation, as well as demodulation of the colliding signals. We show simulation results that demonstrate the gains in performance obtained using the proposed solution.