Simulation Based Optimization of Signal Processing for RFID

Abstract

Over the recent years, an increasing use of near field radio frequency identification (RFID) technologies could be observed. In a near field RFID system, data is transmitted between an RFID reader and an inductively coupled RFID tag. The reader outputs a magnetic field that is used for the power supply of an RFID tag as well as for data transmission. In this work we will focus on the tag-to-reader communication by a method called load modulation. Load modulation means that data is transmitted by switching a resistor at the tag leading to different loads of the magnetic field. This modulates a voltage level in the reader circuit that is detected and further processed at the reader. When increasing the data transmission speed, inter-symbol interference (ISI) occurs. To counteract inter-symbol interference equalization algorithms are used. For designing such algorithms, a fast and precise simulation model is needed. This work presents a novel simulation model for tag-to-reader communication. Performance results of this simulation model showing a significant improvement in terms of simulation speed compared to a traditionally used circuit simulator and performance results of an equalization algorithm developed using this model are shown.