Research On High Efficiency And Robust Anti Collision Algorithm In RFID System

The concept of “the wisdom of the earth” was put forward firstly.It will be realized the real object to be connected in 2009.Subsequently,the government increased the policy and financial support of the related research on the Internet of Things(IoT),and the Chinese IoT entered the high-speed development channel.The new IoT application system was constantly emerging.The IoT is mainly through data collection,information transmission and information processing management and the use of three processes to realize the interactive connection between objects in the physical world and the virtual network world.The data collection process is mainly responsible for sensing the physical environment,collecting real-time physical data and reconstructing the corresponding general concept,and the radio frequency identification(RFID)technology,which is one of the core technologies of the process,is responsible for the identification of the real object and has very important significance in the internet of things.The reader and the plurality of tags constitute a RFID system.When the system works,the reader issues a query command and the tag responds passively.Since all the tags use the same radio channel,if more than one tag responds to the reader and simultaneously transmits the item-related data,the data signal is disturbed,resulting in the reader being unable to correctly decode the received signal resulting in a tag collision problem.The problem of tag collision not only increases the identification delay,but also causes the waste of the bandwidth,has a great influence on the RFID system management operation,and can effectively alleviate the problem by designing the high-efficiency RFID tag anti-collision protocol and improve the efficiency of the tag identification.At present,many scholars have researched and put forward various anti-collision protocols for RFID tags,in general,their system efficiency is still to be improved,especially with the rapid development and wide application of the IoT industry.The requirement of anti-collision technology is also higher and higher for a wide variety of practical application environments.For example,in the application environment where the tag is fast moving,the new tag is continuously added to the reading range of the reader,causing the reading process to be complicated,and due to the rapid mobility of the tag,the part of the tag is moved out of the reading range of the reader without being read,causing the leak of tag.In this case,it is a challenging task to study the fast robust tag anti-collision protocol.The tag anti-collision protocol under the static scenario assumes that no new tag reaches the reader reading area during a round of tag identification,so that the number of the next unidentified tags can be estimated by the tag estimation algorithm through the history information through the previous round identification result.Based on this,the anti-collision protocol is designed and relevant parameters are set.In a dynamic application environment with a tag movement,the tag can join the identification process of each round at any time,the reader does not have the number and ID information of the newly arrived tags,Therefore,it is not feasible to estimate the number of tags in the existing static scenario,so that the protocols under these static scenarios can not run properly in the dynamic scenario,and the problem of serious tag leakage is likely to occur.These and further analyses show that the main reason for the problem of tag leakage reading caused by the existing tag anti-collision protocol is that the protocol does not take into account the new arrival tag and the recognition efficiency is low when determining its parameters.Based on the two reasons,on the one hand,from the perspective of the tag estimation under the dynamic environment and the accuracy of the tag estimation from the dense scene,an efficient anti-collision algorithm for improving the tag congestion problem is put forward.On the other hand,the fast identification of the arrived tag in the mobile scene is proposed,and the system efficiency is greatly improved.The corresponding research results are as follows:(1)A tag estimation algorithm with low computational complexity and more accurate is proposed,and the performance degradation problem of RFID system in a dense tag environment is studied.By adjusting the number of the response tags,the problem of tag congestion is alleviated,and the PMQT algorithm superior to the PRQT is proposed,which is more suitable for solving the collision problem of a large number of tags and has better algorithm robustness.(2)The anti-collision protocol(GSRA)under the dynamic scenario which supports the continuous arrival of the tag is proposed,which is mainly used to solve the problem of the identification of the dynamic frame time slot ALOHA(DFSA)tag anti-collision protocol in the mobile tag environment,and can effectively solve the influence of the arriving tag on the identification process,and the system efficiency is improved.For this purpose,the identification process is divided into two parts,and the existing identification algorithm is still adopted for the newly arrived tag,but for the resident tag which has been identified,its history information can be used on the reader side,the tag can be quickly identified,and the high efficiency of the identification process is realized.The theoretical analysis shows that the system efficiency is only related to the tag mobility and the new tag recognition efficiency.(3)To study the ability of the Hamming weight to distinguish the different tags,it is found that the 3-bit binary can well distinguish the prefix of the tag in the collision process.On this basis,a anti-collision protocol(HWQT)with Hamming-weight mechanism is proposed,which can accurately assign the identification time slot to the tag.The method is simple,at the cost of low prefix cost,the number of the collision frame time slot and the idle frame time slot in the time slot identification stage is obviously reduced,so that the identification performance of the tag is greatly improved,and the theoretical analysis shows that the system efficiency can reach 75 percent.