Research And Implementation Of Network Clock Synchronization System Based On IEEE1588 Protocol

RFID(Radio Frequency Identification)is a short-range wireless communication technology,in which the reader sends a radio wave with specific frequency to communicate with the target and transmit the data.In many situations,multiple readers are required to monitor the target area for reading and processing dense information as the reading range is limited for a single reader,which is called RFID multi-reader system.In a multi-reader system,time division multiplexing is a mainstream technology for avoiding information collision,in which the clock synchronization of readers is one of the key issues to be solved.The full name of IEEE 1588 protocol is Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems.The purpose of this protocol is to minimize the synchronization error and increase the synchronization accuracy.In this thesis,the clock synchronization of RFID multi-reader system is studied based on IEEE 1588 protocol and accurate identification of multiple tags by multiple readers.The main research work includes:1.The message structure of IEEE 1588 was analyzed,and the software timestamp for time synchronization in the original project was replaced by hardware timestamp by using C language in Linux based on the open source code PTPd.2.A hardware system was built to verify the synchronization accuracy of the multi-reader system,and an error of a few microseconds was achieved in the modified project.3.A tag-identification software was developed with C#in.net framework,which combines multiple functions such as read-write,check and session setting together and is suitable for readers to continuously read and write multiple tags.4.The accuracy of the multi-reader system was verified with an oscilloscope and tag-identification software,and multiple tags were accurately identified by multiple readers.