Research On RFID Tag Anti-collision Algorithms Based On Multi-reader Scenario

Radio frequency identification(RFID)is a technology with non-contact automatic identification that uses electromagnetic waves as a transmission medium to accomplish bidirectional data communication.As one of the key technologies of the Internet of Things sensing layer,RFID is widely used in many areas such as intelligent transportation,industrial automation,etc..However,the collision problem in RFID systems has become one of the research hotspots in recent years as the main cause of problems such as a longer identification time,lower accuracy of tag identification,and larger communication errors.Therefore,in the development of RFID technology,an efficient anti-collision algorithm is essential.Collision problems can be divided into tag information collision and reader information collision.This article focuses on the problem of tag information collision.The system structure and the principle of how RFID systems work is introduced at the beginning of this paper,then this paper explains common anti-collision algorithms.Aiming at the problem of “initial redundancy”and the problem of too many collision slots in traditional tag anti-collision algorithms,based on the query tree,two anti-collision algorithms are proposed from the perspective of multi-reader cooperations: The first algorithm locks the initial broadcast layer of the RFID reader at the second last layer of the tree structure,and the collision bits can be identified through Manchester coding to optimize the broadcast nodes,thereby reduces the "initial redundancy" problem.The second algorithm proposes a multireader inverse probability function and dynamically select a tree-structured initial layer.The function focuses on the benefits of different broadcast results,and stores the priority of the queue to be broadcasted in the reader.Broadcast prefixes and results are shared between broadcast readers,the probability of each node is calculated,and then generate the next optimal broadcast node.From the perspective of information interaction,the problem of "tag collision in multi-reader scenarios" is optimized.Simulation results and theoretical analysis prove that the proposed algorithm has less total slots and throughput under the same simulation conditions.The first algorithm has a significant improvement on the "initial redundancy" problem.The second algorithm is able to reduce the collision slots during the query process.Using the two proposed algorithms to reduce the tag collision in tag identification,they can effectively reduce some unnecessary queries and problems such as tag data loss,read and write tolerances caused by collision problems,therefore the efficiency of RFID system is improved.