Biography
Enrollment Date: 2009
Graduation Date：2012
Degree：M.S.
Defense Date：2012.05.24
Advisors：Chun Zhang
Department：Institute of Microelectronics，Tsinghua University
Title of Dissertation/Thesis：Design and Implementation of a Multi-protocol UHF RFID Test System
Abstract:
Radio Frequency Identification (RFID) is an automatic identification technology, which uses the coupling characteristics of electromagnetic waves, and modulates the data in RF carrier through space radiation for wireless communication. Foreign study on the technology is earlier, and has implemented a variety of standards, but in China RFID technology is still in its infancy stage, the technology is not mature enough. The LF and HF RFID products now have been applied in many areas, but the UHF technology has not been universal, and there are still many problems to be solved. One of the most important reasons is that there is no uniform standard, leading to RFID products are not compatible, which brought great challenges to the test technology. Therefore need to establish a common testing platform for compatible standards, to reduce the testing costs of RFID product manufacturers.
Based on the above background, this article using virtual instrument technology combined with digital signal processing, by adopting the software radio platform of National Instrument, design and implement a common multi-protocol test platform for UHF RFID tag, and describe in details of the hardware and software design of the test platform.
This test platform use the FPGA as a baseband processor, which has high speed digital signal processing capabilities, and combined with RF up and down converter to achieve real-time communication of simulation readers and tags. For 18000-6C and user-defined UHF protocol, not only taking into account the hardware's versatility, and also the program design, give full consideration to the structure of reusable and functional scalability.
Use FPGA to achieve transmit and receive path of physical layer, and state control of protocol layer, including the modulation/demodulation, encoding/ decoding, CRC redundancy check, as well as the multi-tag anti-collision algorithms and logic control.
Realize the capture of entire real-time communication process, using RF down-converter and FPGA with high speed data throughput, while take advantage of advanced signal processing tools for embedded controller can analyze the captured signal in time-domain and frequency-domain, display the measurement results graphically, and the data of reader command and tag response is displayed in text. Design a graphical interface for human-computer interaction, easy to operate, test faster. In order to test the tag antenna performance and sensitivity, design a power scan testing and frequency sweep testing.
This test platform can complete the protocol conformance and physical parameters test, and also can dynamically adjust transmission power and protocols parameter. Test results show that the simulation reader work well and can be compatible with both protocols. Not only to be able to read and write single tag, but also can identify multi-tag. Range of communication can be up to 3m, which is at a good level comparable to a real reader.