Research On Adaptive RFID Tag Hybrid Anti-collision Algorithm

Tag anti-collision problem is the focus of current RFID technology research.In the process of identifying,if the collision can not be handled properly,the system efficiency will be greatly reduced.Especially in large-scale RFID systems,the collision will seriously increase the system's identification delay.To speed up the resolution of the tag collision problem,anti-collision algorithms can be designed to constrain tags and set a certain order of response for the tag to avoid or eliminate the collision.Currently,there are a large number of tag anti-collision algorithms,which are mainly divided into three categories of Aloha-based,tree-based and hybrid.It is not difficult to find that the hybrid algorithm can achieve higher recognition efficiency.In addition,more and more researchers pay close attention to design adaptive algorithms,add adaptive ideas to the algorithm,and make some adjustments in conjunction with the actual situation in the recognition process to optimize the whole recognition process.These adaptive anti-collision algorithms can also achieve high recognition efficiency.Therefore,the thesis selects the adaptive and hybrid RFID tag anti-collision algorithm as the research topic.In this thesis,we mainly study adaptive anti-collision algorithm and give a new classification of anti-collision algorithm from the adaptive perspective.Based on the further research of the adaptive anti-collision algorithm,a new adaptive and hybrid anti-collision algorithm is proposed,and then the detailed description of the algorithm and its performance analysis are given in the thesis.The details are as follows.(1)A new classification method is proposed.Combining with the classification basis of existing tag anti-collision algorithm,the anti-collision algorithms are divided into basic adaptive anti-collision algorithm and hybrid adaptive anti-collision algorithm from the adaptive perspective.The basic adaptive anti-collision algorithms based on the Aloha-based or tree-based algorithms,simply adaptive adjust the frame length or multi-tree and base on the collision bit adaptive settings.So the basic anti-collision algorithms are divided into three types according to the specific characteristics,namely,the frame length adjustment type,the multi-tree selection type and the bit tracking type.The hybrid adaptive anti-collision algorithms not only combine the basic Aloha-based and tree-based algorithms,but also it introduces the idea of adaptive adjustment,which assembles several basic algorithms into protocols.Based on the analysis and comparison of two kinds of basic and hybrid adaptive anti-collision algorithms,it is concluded that the hybrid and adaptive anti-collision algorithms have a great advantage in solving the problem of tag collision and can obtain high recognition efficiency.(2)A new adaptive and hybrid tag anti-collision algorithm is proposed.The algorithm combines the bit tracking technology and the optimal partition theory,which consists of two phases,namely,a binary splitting phase and a binary tracking tree identifying phase.The first phase repeatedly divides the set of the current response tags into two subsets by choosing “0” or“1” randomly.After this phase,using the optimal partition theory handles the number of tags in the left subset to obtain the size of slots in the right subset.And then the second phase finishes the identification of tags by utilizing the binary tracking tree slot algorithm on all right subsets in a bottom-up manner.In this paper,the detailed contents of the algorithm are given by using algorithm flow chart and pseudo code.The theoretical analysis and simulation results demonstrate that the proposed algorithm can improve the recognition efficiency of the RFID system and do better in large scale RFID system.