The Research And Design On Structure Of UHF RFID System

Radio-Frequency -Identification (RFID) is a kind of wireless auto-identification technology that bilaterally communicates without contact through RF. As one kind of RFID, Ultra-High frequency (UHF) RFID has some advantages, such as high rapidity of read-write, far distance of identification. Currently, it is the research forward in RFID domain. Firstly, this paper systematically introduces development history and application situation of RFID system; compares and introduces existent three kinds of standard system; introduces RFID's research and development direction. While introduces typical RFID system, this paper analyzes the difference between typical RFID and UHF RFID, and educe the design scheme of UHF RFID.This paper has deeply analyzed ISO/IEC 18000-6 standard. According to requierment of standard, this paper advances design scheme of UHF RFID, includes detailed analysis and introduction of modulation-demodulation module, encoding-decoding module, anticollision module. This paper utilizes NI corporation's development tool--LabVIEW to design the emulate system structure of digital modulation module and baseband encoding module. This program module isn't only be able be used separately, but also can be integrated into a much larger project, provides useful function component for large scale RFID test platform, avoids repeated design.In order to improve one-off identification rate of UHF RFID, after analyzed common-used method for reducing error in communication system, this paper advance amelioration of structure, designs an encoding-decoding module that has special structure, which make CRC encoder and convolution encoder concatenated. This scheme can reduce the time that spent in repeated correspondence at cost of increasing complicacy of circuit to achieve the purpose of improving reliability and practicality of UHF RFID, and use LabVIEW platform to design the key part: Viterbi decoder, gain the correct simulation result.The design above all is realized through LabVIEW software simulation. As virtual instrument development platform that belong to NI Corporation, it has simple and intuitional programming method, has many source code hierarchy device driver, support all kinds of hardware card, can rapidly construct test and control platform for user. This paper construct UHF RFID system based on software wireless idea, provide simple and intuitional platform for research and test on UHF RFID technology.