ArPat: Accurate RFID reader positioning with mere boundary tags

The Radio Frequency IDentification (RFID) technology provides a promising solution to location discovery in indoor environments. Existing RFID reader positioning algorithms usually use all the collected reference tags to determine the position of the target reader, and thus are time-consuming as well as susceptible to the communication irregularity between the reader and reference tags. Especially, they usually perform poorly when the target reader is near the wall or at the corner. In this paper, we propose ArPat, an Accurate RFID reader Positioning algorithm that uses mere boundary reference Tags to calculate the position of the reader. ArPat uses only boundary tags to determine the position of the target reader, which effectively mitigates the negative impact of communication irregularity on the localization accuracy. The localization accuracy of ArPat is higher than 0.2 ft when the space between references tags is 1 ft. Compared with state-of-the-art solutions for RFID reader positioning, ArPat improves localization accuracy by up to 42 percent and 36 percent on average. Furthermore, it uses a geometric approach rather than iterative optimization approaches employed by previous solutions, making it superior in time efficiency. Compared with previous solutions, the computational time of ArPat is nearly two orders of magnitude less. This is critical for a localization system to provide real time location discovery and tracking services.