Research On Anti-collision Algorithm For Passive RFID System

RFID(Radio Frequency Identification) is a new automatic identification technology of contactless. Thought the way of contactless radio communication, it can achieve the goal of automatic identification and data can be transmitted between reader and tags. There are also a lot of problems to be solved. The anti-collision algorithm is one of the most important issues in RFID system. In this thesis, the passive tag anti-collision algorithms are studied and improved algorithm has been put forward. The main works of the thesis are as follows:1) The development and applications of RFID technology have been simply presented. Its anti-collision algorithm and research status have been elaborated. The composition, working principle and collision problem of the RFID system are illustrated.2) The pure ALOHA (PA) algorithm and Slotted ALOHA (SA) and Basic Frame Slotted ALOHA algorithm (BFSA) have been discussed.the Dynamic Frame Slot algorithm (DFSA) has been studied. There are some methods to estimate tag number in DFSA algorithms, those method have been simulated and compared in the thesis.3) Some analysis is made based on the Binary Search Algorithm and its improved algorithms. Such as then Dynamic Binary Search algorithm (DBS) and Backward Binary Search algorithm BBS. Combining the advantages of DBS and BBS, there is Backward Dynamic Binary (BDBS).The amount of communication data is reduced than BBS algorithm. The improved BDBS algorithm (IBDBS) has been presented in witch it takes one bit collision as no collision. The amount of communication data has been reduced and the throughput of the system has been increased than BDBS, the performance of the system has been greatly improved. On the base of improvement of the REQUSET command’s parameters proposed by Li Xueqiao et al, the amount of data has reduced than IBDBS, also has been superior to the algorithm proposed by Li Xueqiao et al.