An Indoor Positioning System Based on the Dual-Channel Passive RFID Technology

In the Internet-of-Things era, it will be increasingly important to accurately and efficiently locate an object in the real world as well as identify it in the virtual world. However, it is not easy to accurately locate an indoor target using radio technology because the multipath propagation of radio waves in an indoor environment may lead to serious position estimation errors. In addition, when each target has a transceiver or each reader operates in its high-power mode, the overall power consumption of the whole system is considerable. In this paper, a dual-channel low-power passive RFID positioning system is proposed to solve this problem. The probability for accurately locating a target within 0.5 m from its real position can reach 96.7% in this system. The positioning area of this work is bigger than those of the prior arts. The total RF radiation power of one block of the proposed system is 23.14 dBm, which is the lowest among reported RFID positioning systems. Furthermore, this proposed architecture can be easily expanded to a large system.