On the power transfer of error-control codes for RFID communications

In this work, we consider the power spectrum of error-control codes designed for the reader-to-tag channel in near-field passive radio frequency identification (RFID) systems using inductive coupling as a power transfer mechanism. In contrast to previous works, binary phase-shift keying is considered, and the power spectral density is computed for two of the codes (and one runlength constraint) considered in a recent paper by Barbero et al. (Inf. Theory Appl., San Diego, CA, 2011), and for two new codes introduced in this paper. Furthermore, we compute the total power transferred to the tag as a function of the inter-coil separation for different codes (and one runlength constraint).