Anti-collision Algorithm For RFID System Based On Continuous Detection

Radio Frequency Identification(RFID) technology is a specific technique identifying thetargets by RF signal. With the rapid development of the Internet of Thing technology and theconcept of “Smart Planet”，RFID has also been given sufficient attention. RFID technologycould exchange and transfer data in the case of non-contact and identify multi-targetsimultaneously. It has high recognition speed and accuracy, secure and reliablecommunications, large label memory storage capacity and many other advantages.In the RFID system, if there are multiple tags in the range of the antenna, tags willrespond the reader simultaneously. Tag collision will happen inevitably. As a result, thecollision problem has become the important factor that influences the efficiency and accuracyof RFID system. In order to solve this problem anti-collision algorithm for tags must beused. After introducing the structure and the technology-based of RFID system, thenon-deterministic algorithm (ALOHA algorithm) and deterministic algorithms (binary treealgorithm) were studied mainly. According to the standard Q-algorithm of ALOHA algorithm,a new algorithm based on the continuous detection mechanism has been proposed. The newmethod has improved the prediction mechanism. Through the analysis of continuouscollision slots with mathematical derivation, results of previous studies is refined. Thenredefines the threshold of Q value adjustment. This scheme can simplify the system andreduce the extra consumption by less detecting timeslot. Simulation results indicate theproposed scheme can improve the efficiency without complicate system.Through the analysis of Bit QT(QT)algorithm and Continuous Collision Bit Detectionalgorithm（CCBD）, a new algorithm based on continuous collision detection mechanismwhich was used in CCBD has been proposed. This new method is called improve continuouscollision bits detection algorithm. The adapted range of the CCBD was expanded bychanging the no-continuous bits to continuous bits. This improvement can eliminate thedependency of continuous collision bits, obtain the actual existence of the continuous collision bits，thereby avoiding the generation of idle timeslots and unnecessary collisiontimeslots. Simulation results indicate the proposed scheme can improve the efficiency, cutdown the delay of query.