Research Of Tag Anti-collision Technology In RFID System

In the1990s, Radio frequency identification began to rise. It is a kind of contactless automaticidentification technique. It develops rapidly in recent years. Featured with the unique contactless andsimultaneous multi-object identification, RFID has the character of rapid speed to read and write, longeffective distance, contactless, large information capacity and good adaptability to environment. Therefore,the application scope of radio frequency identification technique has kept expanding; of course, with thetechnical aspect of maturity, the acceleration of life and the pursuit of efficiency, their performance isdesired higher and higher standards. Anti-collision problem is viewed as a hot issue in the radio frequencyidentification technique. Anti-collision technology plays a very important role in the identification andprocessing of the signal. When the reader sends a request command, all the tags within the effective rangewill transmit data to the reader. Since more than one tag transmits simultaneously, it will produce a signalinterference problem, which is the problem of collisions. In order to enable the information to be readaccurately by reader, we must establish the appropriate protocol in the radio identification system to solvethe problem of collisions. The anti-collision algorithm is very crucial for the reader identifying tags quicklyand exactly. The design of anti-collision technology largely determines the efficiency of the whole RFIDsystem. We should continue to update and improve the anti collision technology. It is a very significantissue to improve anti-collision technology accurately and effectively in RFID.In this paper, the amount of domestic and international literature search, structure and the relevanttheoretical knowledge of the radio frequency identification technology are introduced. The anti-collisionalgorithm is elucidated as key points. In RFID system, there are two types of anti-collision algorithms: oneis based on aloha; the other is based on binary. The Aloha algorithm is very simple procedure, but it has afatal disadvantage that the tags may not be identified forever. Though the binary search algorithm can solvethis problem, it will cause the increase of transfer delay. In order to better solve the problem of collision inRFID system, two novel anti-collision algorithms are proposed in the paper. One is an improvedAnti-collision Algorithm based on Binary search in RFID System; other is hybrid anti-collision algorithm,which is based on Frame Slotted Aloha and Dynamic Binary System Tree Search Algorithm. Theoretical analysis and computer simulations show that the two algorithms all can make RFID system achieve the bestperformance and solve the multi-tag collision in RFID.