Simulation And Implementation Of Anti-collision Algorithm For RFID Tags Based On FPGA

In the 21 st century,Radio Frequency Identification(RFID)technology has become one of the focal points of the Internet of Things(Io T)with its superior performance and potential,attracting widespread attention and interest.the emergence of RFID technology provides a unique capability for the Io T,through wireless communication and automatic identification technology,to enable accurate,fast and contactless identification and tracking.The application potential of this technology is widely recognized in various industries and is seen as one of the key drivers for the development of the Io T.Among the many key factors to enhance the performance of RFID systems,solving the tag collision problem is particularly important.This thesis introduces the research background and importance of RFID technology,describes its development history and current status,and analyzes the composition,working principle and operation process of RFID technology.It also introduces the standard system of RFID system and its practical use in a variety of application scenarios.The tag collision problem in RFID systems is discussed,focusing on the ALOHA-based probabilistic algorithm and the binary tree-based deterministic algorithm,showing the collision model and the identification process.To address the problems in the tag anti-collision algorithm with query tree structure,such as too many idle time slots,time slot utilization and low throughput rate,this thesis investigates the improved query prefix acquisition method,query strategy and FPGA-based algorithm verification.In this thesis,an improved group mapping query tree anti-collision algorithm(IGMQT-AC algorithm)is proposed.The algorithm effectively reduces the probability of collision occurrence through grouping mechanism and mapping mechanism,and at the same time can accurately identify the tag ID grouping where the collision occurs.MATLAB simulation shows that the throughput rate of IGMQT-AC algorithm can reach 67.8%.On the basis of IGMQT-AC algorithm,the anti-collision algorithm of RFID tag based on capture effect(IGMQT-CE algorithm)is proposed by combining the anti-collision ideas in GQT1 and GQT2 algorithms.IGMQT-CE algorithm introduces retransmission mechanism and verification mechanism to effectively avoid the occurrence of tag omission and reduce the negative impact of capture effect on system performance.MATLAB simulation shows that the throughput rate of IGMQT-CE algorithm is about 73.2% when the capture probability is 0.5.Based on FPGA,the key aspects of the IGMQT-AC algorithm are verified.The following key modules of the algorithm are analyzed and simulated using Vivado software and Verilog HDL language: tag control module,Manchester encoding module,Manchester decoding module,data storage module,and reader control module.Through comprehensive simulation tests,all tag recognition is successfully achieved,and the feasibility of the IGMQT-AC algorithm in a hardware environment is verified.In this thesis,the group mapping query tree anti-collision algorithm is improved and the key modules of the algorithm are verified in hardware,which improves the tag recognition throughput rate,enhances the tag anti-collision capability and achieves the expected goal.