The Design Of Passive RFID Location System And Improvement Of VIRE Algorithm

The computing paradigm is coming to the ubiquitous computing era with the rise of internet applications. It offers digital service at any time and at any place. Location-based services technology is one of the core area in the research of computing paradigm. How to get the dynamic location of the indoor users and provide the service they need become a hot topic nowadays. The Radio Frequency Identification (RFID) technology has become the most advantageous technology used for indoor location, because of its non-touch, no light of sight, high accuracy and low cost advantage.In this thesis, the technology of Radio Frequency Identification is introduced firstly, then several exited indoor location technology and algorithm are discussed and analyzed. Finally the VIRE algorithm is selected as the base location algorithm of the location system in this thesis, and several improvements of VIRE algorithm are proposed, including the nonlinear interpolation algorithm, the method of dynamic setting of threshold and the algorithm of correction of the tags in the proximity map. Then the indoor location system based on the R1000 radio development platform, the antennas, and the tags is set up, and the software which controls the system and realizes the algorithm and graphic user interface is developed.Finally the algorithm and the environment factors and all kinds of parameters are tested on the software and hardware of the system platform. The environment includes the height and the angle of the antennas, the temperature and humidity of the environment, the space of the indoor, the environment of the obstacles. The parameters include the number of antennas, the threshold value, the density of the virtual reference tags. The experience showed that the improved VIRE algorithm improved the positioning accuracy significantly. Furthermore, the method through setting proper parameters and environment also can improve the positioning accuracy.