Research And Application Based On The Improved RFID Anti-collision Algorithm

RFID(Radio Frequency Identification) is a technology which not need to be established the direct contact but with the optical contact between the system and the objective,identify a specific target with a radio signal.RIFD system is widely used,as applied in the field of supply chain management,retail trade,air transportation,library management,and so on.Therefore, RFID technology has great potential for development and application.RFID reader system within the recognition range,electronic tags share the radio channel,when a plurality of tag ID simultaneously transmit information to the reader,the reader can not identify a specific tag,i.e.collision,reducing the efficiency of the identification tag reader,collisions will directly affect the integrity of data during transmission.If multiple RFID reader queries a tag or multiple tags within its operating range while sending data to a reader,these two are called interference reader collision and tag collision.Reader collision problem can be solved by rational layout,and tag collision problems are difficult to solve,so this article will tag anti-collision algorithm as the focus of the study.In the RFID system,anti-collision algorithm mainly ALHOA algorithm and its improved algorithm,the binary search algorithm and its improved algorithm. ALOHA algorithm is a series of probabilistic anti-collision algorithm,the transmission time is random,anti-collision efficiency will increase as the number of RFID tags reduced;series of binary search algorithm is deterministic anti-collision algorithm,although the label recognition accuracy of up to one hundred percent,but its efficiency will increase with the number of tags RIFD decline.Based on the dynamic frame slot ALOHA algorithm theory,analysis of various technical parameters of the algorithm proposed an improved algorithm based DFSA.The improved algorithm implementation process is as follows:First,determine the size of the initial frame slots on the first read cycle,the use of Bayesian estimation method for labeling to estimate the number of tags;secondly,from the second read cycle begins,using the maximum frame slot estimation algorithm to assign the most appropriate label frame size;then,if there are too many labels to be identified , then the use of the label grouping strategy;Finally,when the reader can not prejudge the internal system tag number on the label to identify late to join stopping criterion algorithm.The topic of the DFSA algorithm and its improved algorithm simulation results show that the improved algorithm can effectively improve system throughput and reduce the total number of tags to identify the specific number of slots required.Finally,the hospital fixed assets management system,performance testing and validation of the algorithm,the results show that the improved algorithm can effectively achieve the estimated number of tags and identification.