The Design And Research On Digital Baseband Of RFID Reader Based On ISO/IEC18000-6C Protocol

UHF Radio frequency identification (RFID) system consists of reader, tag andcomputer communication network. It has many characteristics such as far affectdistance, easy tracking and management, supporting non-contact identification and highsecurity. It is the foundation for the high technology of collecting data conveniently andprocessing information quickly, and thus contributes to its broad application prospectsin the smart city construction, secure payment, food traceability and data management.Based on the ISO/IEC18000-6C Protocol, this paper first analyzed thecommunication specification for the tag and the reader on the physical layer and datalink layer, and based on this, it analyzed the overall structure of the reader basebandand determined the necessary function module, and setted the parameter for eachmodule as well. Then it made the ASIC hardware implementation for each module. Thewhole reader baseband included the PIE coding circuit, the CRC5circuit, the CRC16circuit, the FM0decoding ciuciut, the Miller decoding circuit, the collision detectingcircuit, the anti-collision circuit, the frequency division circuit, the Timing controlcircuit and the command control circuit ect. The link rate for the reader datatransmission is adjustable.The reader supports the Miller decoding, and theimplementation of Miller decoding is based the regulation of the flag which indicatesthat there is no flip sign between the continuous phase. The floating point value of theslot counter Q in the anti-collision circuit used a variable step, so as to decrease the timewhen reader inventories a group of tags. Frequency division circuit supports the casewhen the frequency divider is a decimal.The whole design completed the RTL design with the Verilog hardware descriptionlanguage. And the function simulation completed based on the test platform. The designcompleted the board level verification in FPGA, and demonstrated the successfulcommunication with the baseband of the tag who has been tap-out and meet theISO/IEC18000-6C engineering requirement, during the communication，the readerbaseband completed the main process of inventorying and accessing a tag.