The Design And Implement Of Long Range RFID System

With the development and maturity of 5G,the Internet of things(IOT)is bound to shine in the era of 5G.As a critical technology in the Internet of things,radio frequency identification(RFID)technology will be applied widely with the rapid development of the Internet of things technology.With the continuous expansion of the application field of passive ultra-high frequency(UHF)RFID systems,the market has placed an urgent need for reliable long-distance communication and large-scale label-free identification,and the main factor limiting the communication distance was the forward link,which was limited by the sensitivity of passive tags.This paper first gave an analysis of the link budget of the traditional UHF RFID system.The result shows that tag's sensitivity limits the effective recognition range.To realize the large-scale long-distance performance of the UHF RFID system,the research work was carried out from three parts: system architecture innovation,hardware module design,and software design.The leading research and contributions of this paper are as follows:1.Based on the current situation that UHF RFID system recognition distance is limited by the sensitivity of tag,a reader-repeater-tag three-point UHF RFID system architecture is proposed in this paper.The distance limit in the traditional reader-tag twopoint architecture is solved,and the communication distance between the tag and the reader is increased by three times to 70 m.2.By using different frequencies between the forward link and the reverse link,the self-interference signal existing in the conventional reader circuit can be eliminated,and the receiving sensitivity of the reader can be improved.3.Through multi-relay networking and multi-antenna coverage,large-capacity RFID tags are cellularized.Combined with space-division,time-division,and frequencydivision,the system greatly enhances the access capability under one reader-many tags scenario.4.In terms of hardware circuit implementation,high-performance reader and repeater hardware circuits were designed to meet the requirements of protocol ISO/IEC18000-6C.5.In terms of software design,A customed internetworking protocol coordinating multi-repeaters was proposed,and the embedded software implementation on the reader and repeater were completed.This paper provided a cost-effective solution for the realization of long-distance RFID systems and catered to the need for mass-tags identification which helps to promote the application and development of UHF RFID technology and cellular Internet of Things.