Propagation characteristics of UHF radio frequency identification system signal for application in indoor positioning

Location information has become very important by the rapid development of wireless communication systems. Specific areas where satellite positioning systems and positioning systems via mobile networks are unavailable, represent a major challenge in gathering information about the position. Most often there is a need for positioning within indoor areas, and one of the systems that can be used for positioning is RFID (Radio frequency identification). Usage of the existing of-the-shelf and certified products can significantly contribute lowering the system's cost. Prior to converting of-the-shelf RFID system into a positioning system, good understanding of system's signal propagation characteristics in indoor environment is mandatory. With this on mind, we investigated propagation characteristics of UHF RFID signal ranging from 865 to 868 MHz in simulated indoor environment using a passive RFID tag. The results show that signal used by the system may be exploited in obtaining the position of the tag.