Design And Implementation Of Key Modules In Novel Distributed RFID-over-fiber Systems

Accompanied by the third world information industry revolution,radio frequency identification(RFID)tecinology which is the key to the realization of the system of things has been in-depth to people's lives.Since 21st Century,RFID technology has made considerable progress and played a more and more important role in a lot of application scenarios.Because of its lower cost in network implementation,the passive tag RFID system based on a single antenna is widely used in widespread scenes with a large number of items.But the advantage of low cost also brings some disadvantage to the system:the limited identification range,the inconvenience of the centralized management on system,and so on.So it is very important for the development of RFID technology how to achieve a scalable RFID system with high precision recognition,centralized management and lower cost.This paper puts forward a new distributed RFID system based on Radio over Fiber(RoF)technology to solve the above problems.RoF technology is a new kind of wireless access technologyy,which is developed rapidly in recent years.It is a perfect combination of optical fiber communication and wireless communication.In this paper,we propose a method to combine the RFID system and the RoF technology,which is the key to the novel distributed RFID-over-Fiber.The new system brought us a lot of benefits.Besides that,there are two difficulties that are the problem of self-interference cancellation and the problem of centralized management of distributed network when we implement the new system.In one hand,the self-interference signal has a worse effect on the normal operation and receiving sensitivity of system after the RoF technology is integrated into the traditional RFID system.To solve this problem,this paper presents the technology of self-interference signal cancellation which can achieve the inhibitory effect of 11dB through the experiment.On the other hand,we need a way to connect the devices with serial ports into the Internet so that system can realize the centralized management in the distributed network structure.In order to guarantee the low error rate and high efficiency of system,this paper proposes the multi-serial-Ethernet data converter,which can make the serial data stream convert to the Ethernet data stream based on TCP/IP protocol.