Object localization using RFID

Object localization is a key primitive in pervasive computing environments, where numerous applications depend on the rapid and accurate position estimation of objects. We present a general RFID-based localization framework that reliably determines the positions of objects with unprecedented accuracy and speed. This is achieved by varying the power levels of the RFID readers, calibrated against reference tags of known sensitivity. Our implementation and experiments are able to localize objects to an accuracy of 15 cm within a few seconds, and this compares favorably with previous techniques. We also suggest several practical optimizations for further enhancing the speed and accuracy of the method.