Research And Performance Analysis Of Anti-collision Algorithm For RFID System Based On Linear Pro-coding

Radio frequency identification technology is a kind of non-contact automatic identification technology,which using the transmission characteristics of radio frequency signal and space coupling to carry out two-way communication.RFID has a lot of advantages such as high efficiency,large storage,reliability.RFID is one of the core technologies of the Internet of things,with the development of the Internet of things technology,which is applied in many fields widely including logistics,intelligent transportation,bio-electronics and industrial automation.In the RFID system,there are two kinds of collisions which are reader collision and tag collision.But most of researches are focused on the tag collision due to the small probability of reader collision and strong ability of information processing.Tag collision is multiple tags simultaneously respond to the reader’s query command in tags jam applications.It is essential to improve the performance of radio frequency identification by designing anti-collision algorithm which can reduce and avoid collision to a great extent.In this paper,some improvement and innovation have been done based on ALOHA algorithm and linear pre-coding technique.The mainly improvement and innovation points are as follows:(1)This paper proposes a zero-forcing pre-coding algorithm based on frame time slot which combined frame time slot algorithm and zero-forcing pre-coding technology.Tags are pre-coding before transmission by zero-forcing pre-coding technology so that it can reduce the error or collision of the tag during transmission or reception.The simulation by MATLAB results show that the tag identification rate and performance of the algorithm have been improved.When tags number is about 1000,tag identification rate of the improved algorithm is about 0.7.Compared with ISE-BS algorithm,DGBT algorithm and FSA algorithm,the improved algorithm has enhanced tag identification rate by 83%,20% and 300% respectively.(2)This paper proposes a minimum mean square error pre-coding algorithm based on frame time slot which combined frame time slot algorithm and minimum mean square error pre-coding technology.The zero pre-coding technology completely cancels the interference between different antennas and separates different data streams,but at the cost of noise.And minimum mean square error pre-coding technique use the minimum mean square error as the criterion,minimize mean square error between symbols and detector output estimate,which means it considers the effect of noise on algorithm.The simulation by MATLAB results show that when tags number is about 1000,tag identification rate of the improved algorithm is about 0.8.Compared with RLAMS algorithm,RBST algorithm and FSA algorithm,the improved algorithm has enhanced tag identification rate by 52%,58% and 340% respectively.The new anti-collision algorithm proposed in this paper can provide better tag identification rate and lower identification cost,which is applied in military,traffic monitoring and bio-electronics.