The Research Of RFID System Tag Identification Algorithm Based On FPGA

Radio Frequency Identification technology is a technology which utilizes space coupled RF signal transmission or reflection wave characteristics to achieve non-contact automatic identification. Compared with the traditional means of identification, RFID has contactlessly identification, widely recognition range, high reading speed, strong anti-jamming capability, multiple tags can be read at the same time, etc., in social security,logistics management, public security, telecommunications, finance, intelligent transportation,public utilities and many other areas are widely promoted. When there are multiple tags simultaneously existing reader's read range, the collision of the sent data from each tags will greatly impede the correct identification of tags. With the continuous improvement of RFID technology, In RFID systems, multi-tag identification with collision problem become a hot research topic. Therefore, the research of multi-tag anti-collision identifying algorithm is of great practical significance.This paper firstly introduces the basic principles and classification of radio frequency identification technology.and so introduces its Algorithm validation platform. As for information identifying, mainly researches the problem of anti-collision handling mechanism.Focuses on the evolution direction of the pure Aloha algorithm, slot Aloha algorithm, frame slots Aloha algorithm and the dynamic frame slotted Aloha algorithm. Research the basic binary arithmetic, dynamic binary arithmetic and retrusive binary arithmetic's characteristics.And on this basis, concludes an improved prefix query algorithm.Thesis researches the implementation of anti-collision identifying algorithm in the RFID system on FPGA platform. In the selection of coding mode, comparing the characteristics of unipolar and bipolar symbols, focusing on process of Manchester(bipolar code) encode and decode hardware implementation, and analyzes design details. As for improved binary anti-collision identifying algorithm, using Verilog HDL implemented its emulation specificly on the FPGA platform. the reader realized automatic anti-collision identification, and verified operability of algorithm on Spartan6 platform.Experiment results prove that comparing with dynamic binary algorithms and retrusive binary algorithm, the improved prefix query algorithm has a higher efficiency in anti-collision identification.