Localization of handheld UHF RFID reader using reference tags in 3D environment

It is very important to determine the location of a handheld UHF RFID reader unit in the management of library or warehouse based on RFID system. In reality, the management of the library or warehouse is performed in the 3D space. It is necessary to determine the location of the handheld UHF RFID reader in 3D indoor environment. The localization of the handheld UHF RFID reader can be done using the reader with a function of receiving the backscattered signal from tags. The location of the reader unit in indoor environment can be determined by one method that detects tag ID nearby the reader using RSSI of backscattered signal from 3D arrayed reference tags. In this paper, we proposed one method that a handheld UHF RFID reader unit determines its location by itself using 3D arrayed reference tags fixed on the shelves placed in the libraries or warehouses and proved this method through experiment results.