Localization of objects using passive RFID technology

This paper presents a localization method based on passive Radio Frequency Identification (RFID). Information that is acquired during the radio information transmission between a tag and the reader is analyzed for this purpose. Resulting parameters allow a statement of the distance between the communication partners. Using several readers with known positions and a motion model of the tags an estimation of the three dimensional position of the tags is possible. For that purpose it is necessary to compensate failures and defects in the radio channel caused by the environment and the object that carries a tag. Our approach uses a Bayes-like filter approach. Our prototype provides positioning accuracy in the decimeter range.