Research And Implementation Of Conformance Test Technolo-Gie Of 2.45GHZ RFID GB/T 28925 Based On Pxie Modular Instruments

2.45GHz RFID technology has been developed rapidly and proposed as the solution to problems in physical distribution management, man monitor and shipborne identification. Due to the diversity and difference of the RFID requirements and standards, traditional test instrument is unable to meet the demand of global industry, and a software-defined real-time test instrument of high performance becomes necessary. This paper is centered on the design and implementation of the GB/T 28925 RFID tag conformance test in 2.45GHz, which is based on the PXIe modular instruments platform. Main contributions are as follows:Firstly, the basic principles of RFID system working at 2.45GHz are studied in detail. We described the basic framework and key technologies in communication process of semi-active tag system. A dual band communication scheme is proposed for semi-active tag, which uses external awake signal at a low-frequency and backscatter modulation principle of data transmission at a microwave-frequency. O-QPSK and DBPSK modulation schemes are discussed, and simulation results are given afterwards.Secondly, the key technology of the GB/T 28925 air interface protocol is researched and illustrated. we research on the communication link between Reader and Tag, including operating frequency, modulation mode, data rate in physical layer and frame format of data, state transition of tag and protocol working mode in data link layer. We also describe the test requirement and test method of the RFID test system. This part has laid a theoretical foundation for implementing the conformance test system.Thirdly, the RFID test system based on the NI module instruments is constructed, including underlying FPGA RFID reader prototype and upper PC test module. With the clock nested state structure, we make a combination of physical layer transmitter, receiver and data link layer to realize the RFID reader prototype which supports two kinds of modulation as O-QPSK and DBPSK.At last, a complete test system is constructed by adding upper PC test module based on RFID reader prototype. Test module consists of tag RF and protocol conformance test, such as Joint Time-Frequency Analysis, code rate, tag response time, tag command response and tag state transition etc. Specific theoretical analysis, description of program and test results are given for each test module.In a word, the RFID conformance test system designed in this paper is real-time interactive, extensible and flexible.