Research On Some Key Technology Of RFID

Radio Frequency Identification, as a fast real-time accurate information collection and procession technology, has been concerned as one of the ten most important technologies in the world. Consequently, the research of the important technology about RFID has a good effect upon the future of the development of RFID.This paper introduces two important technology of RFID. Firstly, as now many RFID readers in the market can only identify tags applying for a signal protocol, a design scheme of a multi-protocol RFID Reader is put forward in order to identify tags tallied with two protocols after comparing some RFID reader's design scheme. The reader first classifies tags, and then uses different ways to control different kinds of tags. The radio frequency chip is suitable for two different modes of modulation and demodulation. The controller has two ways of control and its order determines what mode the chip will choose.Another important technology——anti-collision is also researched. Because the main method of TDMA is ALOHA algorithm and binary tree algorithm, they are researched in the forth and fifth chapters. As some binary algorithms in common use can't satisfy the standard of times of search and the length of order, an improved dynamic digital algorithm used for protocol ISO14443 is put forward, which uses the position of collision as a clue. The theoretical ratiocination and simulation demonstrate that this algorithm is better than other three algorithms. Taking aspect of the algorithm based on ALOHA, because the tags transmit data to the reader in a circulation, the efficiency will decrease when the number of tags increases. A slot-ALOHA algorithm with protocol ISO15693 is put forward in the paper. It divides the time of transmission into 16 slots. After the tags receive the command of the reader, they will choose the proper slot to transmit datum. The simulation results of the slot-ALOHA demonstrate more efficient than ALOHA algorithm.Finally, the paper summarizes the research results and points out the directions of further research.