Implement Of The RFID Reader And Study Of Anti-collision Algorithms

With the flow of goods increasing in the logistics system, the embedded RFID reader devices have been indispensable in the logistics identification system. In order to automatically identify the e-tag of logistics system, This thesis designed and implemented an embedded radio frequency identification (RFID) system. The thesis mainly studied the embedded system operating systems, RFID application software and the e-tag anti-collision algorithm.The thesis using the Intel PXA270 microprocessor as the core in the implementation process of system, and build an electronic tag reader's hardware platform to realize the device of electronic tag reading; existing embedded Linux operating system was cut and secondary developmented, and designing the system application software, including embedded operating system and application in the signal encoding and decoding process, interrupt program, frequency hopping control program, matrix keyboard driver, antenna transceiver control program, serial communication drive and network interface program.The e-tag conflict intensified In the large-scale tag identification process, resulting in performance degradation of the reader, so resolving the e-tag conflicts is an important part of RFID systems. Anti-collision algorithm of the e-tag, the traditional binary search algorithm uses the serial number of bits blind comparison, the number of iterations increases with the number of tags enable iterative calculations and operational efficiency is low; dynamic binary search algorithm is to avoid a blind bit comparison, but identification of each e-tags are required to conduct another global search and can not handle very well to achieve greater efficiency. In this thesis, back upward a level search strategy is designed to reduce the total search number of iterations based on the dynamic binary search anti-collision algorithm, improved efficiency of the identification tag. Algorithm to meet the requests of all the effective range of the e-tag sequence, starting from the first stage dynamic creation of a tag-level inverse pyramid, when the tag is identified in a certain level, the search level up back level at the previous level on the e-tag another round of iterative search until all tags are identified. The results show that back up a dynamic binary algorithm, reducing the overall number of searches, has a higher recognition efficiency.This paper is designed for embedded radio frequency identification equipment to the application requirements, using the improved anti-collision dynamic binary search algorithm improves the processing efficiency of tag identification operations. The system is in the business logistics system has practical value.