Constrained codes for passive RFID communication

This paper addresses coding for power transfer, modulation, and error control for the reader-to-tag channel in near-field passive radio frequency identification (RFID) systems using inductive coupling as a power transfer mechanism. Different assumptions on channel noise (including two different models for bit-shifts, insertions and deletions, and additive white Gaussian noise) are discussed. In particular, we propose a discretized Gaussian shift channel for the reader-to-tag channel in passive RFID systems, and design some new simple codes for error avoidance on this channel model. Finally, some simulation results are presented to compare the proposed codes to the Manchester code and two previously proposed codes for the bit-shift channel model.