Abstract
The passive Ultra High Frequency (UHF) RFID tag localization technology has attracted more and more attention in recent years, due to its advantages of low cost, simple deployment and long-distance communication. Most researches use the Received Signal Strength (RSS) of the tag backscattered signal or reference tags to realize localization. Owing to the large fluctuation of RSS and its sensitivity to antenna direction and environment, the localization accuracy is meter-level and can hardly be further improved. Reference tag based localization systems are complex to deploy and consume more resources. To solve these problems, a passive UHF RFID localization algorithm based on carrier phase and distance difference is proposed in this paper. A large virtual bandwidth is obtained by frequency hopping technology to improve the multipath resolution. Benefiting from the high multipath resolution provided by the large bandwidth, a modified Frequency Hopping Continuous Wave (FHCW) ranging algorithm is proposed to suppress the multipath effect on phase and solve the phase cycle ambiguity. And the Least Square (LS) method is adopted to realize two-dimensional localization. Simulation results demonstrate that the proposed FHCW algorithm can achieve ranging accuracy of 2 cm, and the probability is more than 97%. Under the triangle layout, the proposed localization algorithm can achieve localization error of less than 6 cm.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
