A Dual-RFID-Tag Based Indoor Localization Method with Multiple Apertures

This paper proposes a dual-RFID-tag based localization method with multiple-aperture to estimate the location and orientation of the object, which preserves high resolution of the large aperture of the antenna array while eliminating position ambiguity by using the small aperture of the two tags attached to the object. The observations obtained by the large and small apertures are synthesized to form linear equations where the object orientation is first solved and then used to estimate the position. To evaluate its performance, the proposed method is implemented using the commercial RFID equipment. Results show that the proposed method can achieve a localization accuracy of about 9.4 cm in the two-dimensional (2-D) area and outperforms the state-of-the-art antenna-array-based localization methods.