Research Of Indoor Localization Technology Based On Radio Frequency Identification(RFID)

With the fast development of Internet of Things,the relationships between people and things become more closer.Localization information plays an important role for improving the efficiency of our daily life and work,so localization technology is one of the most popular aspects in scientific research.Radio Frequency Identification(RFID)which is widely applied to the indoor localization has the advantages of non-contacting,non-line-of-sight,automatic identification and so on.LANDMARC localization system is used typically by comparing received signal strength indication(RSSI)between reference tags and tracking tags to find K nearest neighbor tags whose weights are decided by the deficiencies.LANDMARC has a better localization accuracy compared with other localization systems.However,the number of reference tags is limited in one system,LANDMARC lacks an error checking method and the localization costing time can be reduced more.Aiming at improving the performance of LANDMARC,an improved system layout with error checking method is introduced with virtual reference tags which RSSI are set by the log-distance path loss model and environment compensation dosage.As for reducing the time cost,using a rough localization method combined with region division can have better time efficiency.In order to get the position information,a 2.4GHz RFID localization system is designed by choosing CC2500 as the radio frequency chip which can detect the RSSI and MSP430 as the MCU.After hardware designing,the reader can communicate with the tags to finish the location algorithm by software designing,meanwhile a anti-collision algorithm based on the CC2500's characters is introduced.The last part is about experiments and simulation.The RSSI can be detected and position information can be showed by the designed system which is easy to build and can fit the environment fast and properly,the system meets the basic requirements of indoor localization.In the MATLAB simulation parts,the improved LANDMARC shows better localization performances contrasted with LANDMARC and VIRE,so it is feasible when fewer but necessary reference tags are chosen by rough localization or region division,the time efficiency becomes much better.