Research On Anti-collision Algorithm In RFID

RFID(the Identification of the Radio Frequency),is a kind of automatic identification technology which has been developing since 1980s.It communicates and exchanges data bidirectionally and contactlessly through radio frequency for the purpose of identification.The RFID system is playing an important role in logistics supply chain gradually,such as goods tracking,stock management,etc.The RFID system provides a most convenient and useful implementary project for the logistics supply chain management.Its application includes product authentication,quality control,storage management,logistics supply,stealing examination,automatic accounts settling,etc.However,the potential of RFID market still can't be estimated in the future.Two greatest characteristics of RFID technique,unmanned work intervention and repeated use,show the huge potential and application foreground in RFID.With the further lowering of the price of RFID labels,the RFID technique will have more advantages and attractions.This thesis researches anti-collision algorithms of RFID system.Firstly,it introduces the development process,classification,characteristics,domestic and international present condition of research and development in RFID,the fulfillment meaning and the applied obstacle in logistics management,present condition of studying anti-collision algorithms in RFID system briefly.Based on introducing the foundation of the structure and workflow of the RFID system briefly,it stresses to discuss one of the key techniques of RFID——anti-collision algorithm, summarizes the project of anti-collision,introduces two existing major types anti-collision algorithms,and carries on comparing and analyzing necessarily.Then it imitates ALOHA algorithm and other algorithms which come into ALOHA algorithm,improves the existent algorithms,and verifies the improved algorithm by imitating with MATLAB.Chapter 3 and chapter 4 are the key chapters in this thesis,it studies Class 1 and Generation2 protocols which support to communicate between readers and tags, analyzes and compares the fixed frame slot ALOHA algorithm and dynamic frame slot ALOHA algorithm.Aiming at the anti- collision problem in communicating between readers and tags,an improving dynamic frame slot ALOHA algorithm is designed.Under the circumstances of many tags taking part in identification,the algorithm estimates existing the number of tags and groups,then each group transfers dynamic frame slot ALOHA algorithm respectively,estimates the number of collision slots in each group and adjusts the number of slots in a frame.Thus the efficiency of the system is raised and the stability of the system is strengthened. Besides,it models and imitates with MATLAB according to this project,and compares and analyzes the result of imitating,verifies the accuracy and possibility of the model.Finally,it sums up and analyzes the research contents and the shortage of this thesis,puts forward an outlook for further research.