Research About RFID Tags Hybrid-Anti-Collision Protocol

Technology of Radio Frequency Identification (RFID) is non-contact and automatic identification. RFID technologies have innovated the tracking industry, and applications is very broad. Facing more and more tag numbers, the promise of tag reading is brightly, especially these applications are so fast and energy efficient. In fact, tag reading algorithms face many problems. A key one being tag collision, which occurs when multiple tags reply simultaneously to a reader. In this case, an RFID reader experiences low tag reading performance, and wastes valuable energy.This thesis focus on researching tag's an-collision algorithm of RFID system. Firstly, it introduces researching background. At the second place, analying domestic and international present condition of research. Then based on simply introducing the RFID-system's structure and working process, it mainly discuss RFID an-collision protocols at present. At the same time, making a comparison of aloha algorithm, tree algorithm and hybrid algorithm. Further more, to analysis the common tag an-collision algorithm from simulation. And from this, we present an improved protocol----hybrid algorithm of collision inversion, and through the MATLAB simulation to analysis and test it.Hybrid algorithm of collision inversion makes full use of the advantages of aloha algorithm and tree algorithm, which combines time mechanism of aloha, and collision inversion of the other. Particularly, because of the code table, it can make full use of the former collision to arrange subsequent slots and reduce collisions. Dealing with the idle slots, this algorithm adapt "early end", which can speed up the tag access, to reduce the time of idle slots. Finally, simulation experiments show that the new one is better than the common algorithms, and is really accelerating the access speed.