Research Of Anti-collision Algorithm Based On RFID System

Radio Frequency Identification (RFID) is a high-speed, real-time and accurate information acquisition and processing technology. It appears along the popularity of radio technology and LSI applications. It is recognized as one of the top ten important technologies of the21st century. This RFID technology uses the radio frequency signal through the space coupling to realize non-contact two-way data transmission. Therefore, the indentity-relevant information is obtained to recognize the targets automatically. In contrast to the other automatic identification technologies, RFID has many advantages such as far identification distance, high recognition speed, high precision, long service life, and immune to the target direction and position.RFID system is composed of electronic tags, reader and communication network. Antenna is used to transfer data and energy between the electronic tags and the reader. The identity information is burned into the tag in advance. The tag responses to the reader in the reading scope. Reader reads the data, and transfers the data to the communication network. In the RFID system, there are usually two types of communication collisions, one is the reader collision, and the other is the tag collision. In this thesis, we mainly study on the tag collision.RFID system has many kinds of anti-collision technologies. With regard to the form of communication, the power, the complexity and the cost, the TDMA method is commonly selected. There are basically two kinds of TDMA-based anti-collision algorithms:the ALOHA algorithm and the binary-tree algorithm, which are fully reviewed in the thesis. After that, we propose two new anti-collision algorithms:GBS algorithm and CRB algorithm. The performance of the two new algorithms is analyzed in detail. The analysis results show that although the first algorithm combines with the advantages of the two kinds of traditional algorithms, it is only applicable to some particular cases. The second algorithm is suitable for general situation, and the system efficiency can always keep stable in a higher level. The new algorithm has certain theoretical value.