Dual Type Communication Range Recognition Method (D-CRR) for Indoor Position Estimation of Passive RFID Tags

Recently, the radio frequency identification (RFID) system is paid attention as an identification source that can realize a ubiquitous environment. One of the important technologies that apply the RFID system is the indoor position estimation of RFID tags. For example, it can be applied to an indoor navigation system for handicapped person and recognition of ambient environment by a mobile robot, etc. In this paper, we propose a new positional estimation method to estimate the RFID tag position by using the tune of the antenna directivity of the RFID reader (D-CRR). This method controls the directivity of the antenna by dynamically changing the distance between the antenna elements of the RFID reader. We show the effectiveness of the proposed method by computer simulations.