RFID防碰撞时隙应变协处理算法研究  

Research on RFID Anti-Collision Algorithm of Slot Responding in Real-Time and Co-Processing

作　　者：张小红[1] 张留洋[1] 

机构地区：[1]江西理工大学信息工程学院,江西赣州341000

出　　处：《电子学报》2014年第6期1139-1146,共8页Acta Electronica Sinica

基　　金：国家自然科学基金(No.61363076);江西省教育厅重点资助项目(No.GJJ13435);江西省研究生创新专项资金项目(No.YC2012-S092)

摘　　要：射频识别(Radio Frequency IDentification,RFID)技术具有同时识别多个标签的能力.由于标签随机占用信道会使响应信号发生混叠,当大量的标签在读写器感应区域内同时响应势必会引起标签碰撞问题,严重影响了RFID的系统吞吐率.为进一步提高RFID系统吞吐率,在不增加标签端算法复杂度和硬件的条件下,本文提出了预设调整盘存周期的差分门限、时隙前向检测后向预测和二进制散列的方法,协同处理当前时隙和下一个时隙的标签响应情况.利用预设差分门限的方式避免读写器进行浮点运算,同时通过时隙前向检测和后向预测的方法提前判别当前时隙和下一个时隙的标签响应情况,然后快速跳过当前空闲时隙和下一个空闲时隙,并对在当前碰撞时隙和下一个碰撞时隙响应的标签实时进行二进制散列.通过盘存周期调整方式比较、时隙散列方式对比、识别时延与吞吐率比较三个仿真实验,结果显示改进的算法提高了读写器的计算效率,明显减少了无效时隙占用信道的时间,RFID系统吞吐率可提高到52%以上.Although RFID（Radio Frequency Identification ,RFID） is capable of identifying multiple tags synchronously ,the tag collision occurs inevitably when a large number of tags respond in the induction area of reader simultaneously ,which seriously influences the throughput of RFID system because signal aliasing arises from tags occupying the channel randomly .In order to fur-ther improve the throughput of RFID system ,this paper proposes a new anti-collision algorithm with adjusting inventory cycle by the preset difference threshold ,the slot checking forward ,the slot predicting backward and the slot binary splitting ,which are coordinate-ly combined to deal with the response of the current slot and the next slot when algorithm complexity and hardware are not added in tags .In the algorithm ,the preset difference threshold can prevent reader from floating point computation .Meanwhile ,the methods of slot checking forward and predicting backward are joined together to judge the response of the current slot and the next slot in ad-vance ,which can skip the current idle slot and the next idle slot ,and split the tags responding in the current collision slot and the next collision slot in real time .In the following three simulation experiments ,ways of inventory cycle adjustment ,methods of slot splitting ,the identification delay and throughput are compared respectively .The results indicate that the improved anti-collision algo-rithm can raise the computation efficiency of reader ,effectively reduce the time of channel occupied by invalid slots ,and as a result , the throughput of RFID system can reach more than 52% .

关 键 词：射频识别 防碰撞算法 差分门限 时隙前向检测 时隙后向预测 

分 类 号：TN911.23[电子电信—通信与信息系统]