Research Of Indoor Positioning System Based RFID

With the rapid development of mobile and wireless communication technologies,wireless indoor positioning technology requires more and more applications are increasingly widespread.In the outdoor positioning,GPS and other global satellite positioning system and wireless cellular positioning systems have been widely used in various aspects of life.In the indoor positioning system,the Zig Bee positioning technology,Ultrasonic positioning technology,Infrared positioning technology,Bluetooth positioning technology,radio frequency identification(RFID)positioning technology and Wi-Fi positioning technology,but because of the indoor environment is more complex,severe multipath Effect,most of these techniques is not very good positioning.In contrast,radio frequency identification(RFID)technology also has the advantages of low cost,non-line,non-contact,etc.,and can be combined with Internet communications technology,goods identification and tracking information sharing worldwide.This article first RFID indoor positioning system associated with RFID technology and TOA,RSSI,TDOA and other localization algorithm overview,then RFID indoor positioning is the classic algorithm LANDMARC based on analysis of its working principle,performance characteristics and may influence the positioning accuracy of a variety of factors,and the algorithm is exploratory research.Articles on two aspects LANDMARC algorithm is improved.First,the positioning of the grid area.The case of the reference label location within the region meshing process,that is more detailed treatment of the RSSI values for each reference labels,so without increasing the reference labels can be measured more accurately determine the location of the label.Second,the treatment of choice test label adjacent reference label has been improved.Improved clustering algorithm uses the idea of choice and tag RSSI value measured closest reference label adjacent to the label,so you can ignore the reader to various influences between labels,thus more accurately show the actual position of the test label.Finally,the improved algorithm Matlab simulation.Simulation results show that the improved algorithm at the vast majority of cases the error is less than the original LANDMARC algorithm,the average positioning accuracy relative to the original algorithm increased nearly 3 times.