Research On UHF-RFID Localization Technology

Radio frequency identification technology (RFID, Radio Frequency Identification) is an emerging automatic identification technology with variety advantage. Such as non-contact, long-distance, low cost label, non-visual, quick identification of multi-objectives. These advantages make RFID technology ideally suited for wireless positioning. RFID-based location system has been frequently researched and gradually become dominant technology for indoor positioning.This thesis utilizes the RFID system in the library by analyzing the interior of library to discovery positioning demand of books in the library. This thesis firstly introduces the structure, working principle of the RFID technology and coupling methods, and describes the physical principle of RFID positioning system. Then according to core idea, this thesis gives a brief introduction on application development of RFID technology in library. This thesis introduces4methods of RFID indoor positioning technology and then gives a brief introduction of work principle, advantages, disadvantages and feasibility.Based on the actual condition and feasibility, we adopt RSSI-based positioning system to locate the label. In positioning system design stage, five readers’receiving intensity values are adopted, we select four max values calculate corresponding readers’position coordinate, so as to gain coordinate area of the DUT label. When Weighting coordinates, author of this article derived weighting formula based on the four Reader’s values, combined weighting formulas and location coordinates, we finally locate the position coordinates of DUT label.Firstly, we draw a large number of simulation data according to proposed algorithm, and then draw the positioning accuracy curve. Move the tag’s position, draw accuracy curve of the different position.Then we calculate impact of algorithm accuracy by changing the signal-to-noise ratio, two simulations in the mare based on the LANDMARC algorithm, the purpose is to compare improvement of accuracy of the proposed algorithm and LANDMARC algorithm.On the basis of MATLAB simulation results, in proposed positioning system,84%of the positioning error are within0.3m,90%of which within0.4m.