Location through proximity in RFID systems

In this paper we introduce Location Estimation through Proximity Information (LEPI), an algorithm that aims at locating portable RFID readers in areas where active-RFID grids are settled. Location estimation is accomplished through a proximity information, which the reader derives by performing tag interrogation at increasing RF power levels. RFID tags surrounding the reader are incrementally detected and their known positions are eventually averaged, this providing an accurate estimation of the reader location. The performance of the proposed approach is assessed by experimental trials, conducted in indoor environments. They testify both to the actual feasibility of such a solution and to its better accuracy when compared to other reference RFID-based location techniques.