Coding for passive RFID communication

Abstract

This dissertation elaborates on channel coding for reliable communication in passive RFID systems. RFID applications have been developed and used widely. Since a passive RFID tag has no power requirements, passive RFID has received considerable attention for application to sensor networks, access management, etc. A passive RFID system transfers energy together with information by means of inductive coupling. Coding schemes design for inductively coupled channels is the main task of this work. Due to the properties of inductive coupling, the communication over the inductively coupled channel has synchronization loss problems in addition to other classical channel errors. We therefore design codes that consider synchronization loss, energy transfer, transmission rate, and complexity of encoding and decoding. Because of the different properties of reader and tag, the coding schemes for a passive RFID system are designed differently for the two directions between a reader and a tag. In this dissertation, electronic circuits as infrastructure for the physical layer of the system are described. Modulation codes, error control codes and constrained codes, including their algebraic and structural properties, related algorithms, and techniques are addressed. Code combination and code power spectra are also considered as important issues in the code design that improve the ability of error detection and correction.