Abstract: In order to solve the radio frequency identification (RFID) positioning problem, the working principle, advantages and disadvantages of two positioning methods (AOA and TDOA) were analyzed in detail by comparison, on the basis of which, an indoor positioning hybrid approach of Ultra High Frequency (UHF) RFID was proposed. This proposed approach took the AOA as the core and integrated the idea of time diference in TDOA. Moreover; the stepping motor and UHF reader were used simultaneously instead of antennas array to make UHF RFID reader whirl around an axis. Therefore, it is easy to scan each tag that can be found with the constant angular rate cand estimate their locations. The simulation results indicate that the accuracy of hybrid approach is better than separate positioning algorithm, which is a more effective and more precise positioning technology.

Key words: RFID, AOA, TDOA, passive UHF, hybrid approach