电子学报
電子學報
전자학보
ACTA ELECTRONICA SINICA
2014年
6期
1139-1146
,共8页
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
射頻識彆%防踫撞算法%差分門限%時隙前嚮檢測%時隙後嚮預測
사빈식별%방팽당산법%차분문한%시극전향검측%시극후향예측
RFID%anti-collision algorithm%difference threshold%slot checking forward%slot predicting backward
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。
射頻識彆（Radio Frequency IDentification ，RFID ）技術具有同時識彆多箇標籤的能力。由于標籤隨機佔用信道會使響應信號髮生混疊，噹大量的標籤在讀寫器感應區域內同時響應勢必會引起標籤踫撞問題，嚴重影響瞭RFID的繫統吞吐率。為進一步提高RFID繫統吞吐率，在不增加標籤耑算法複雜度和硬件的條件下，本文提齣瞭預設調整盤存週期的差分門限、時隙前嚮檢測後嚮預測和二進製散列的方法，協同處理噹前時隙和下一箇時隙的標籤響應情況。利用預設差分門限的方式避免讀寫器進行浮點運算，同時通過時隙前嚮檢測和後嚮預測的方法提前判彆噹前時隙和下一箇時隙的標籤響應情況，然後快速跳過噹前空閒時隙和下一箇空閒時隙，併對在噹前踫撞時隙和下一箇踫撞時隙響應的標籤實時進行二進製散列。通過盤存週期調整方式比較、時隙散列方式對比、識彆時延與吞吐率比較三箇倣真實驗，結果顯示改進的算法提高瞭讀寫器的計算效率，明顯減少瞭無效時隙佔用信道的時間，RFID繫統吞吐率可提高到52％以上。
사빈식별（Radio Frequency IDentification ，RFID ）기술구유동시식별다개표첨적능력。유우표첨수궤점용신도회사향응신호발생혼첩，당대량적표첨재독사기감응구역내동시향응세필회인기표첨팽당문제，엄중영향료RFID적계통탄토솔。위진일보제고RFID계통탄토솔，재불증가표첨단산법복잡도화경건적조건하，본문제출료예설조정반존주기적차분문한、시극전향검측후향예측화이진제산렬적방법，협동처리당전시극화하일개시극적표첨향응정황。이용예설차분문한적방식피면독사기진행부점운산，동시통과시극전향검측화후향예측적방법제전판별당전시극화하일개시극적표첨향응정황，연후쾌속도과당전공한시극화하일개공한시극，병대재당전팽당시극화하일개팽당시극향응적표첨실시진행이진제산렬。통과반존주기조정방식비교、시극산렬방식대비、식별시연여탄토솔비교삼개방진실험，결과현시개진적산법제고료독사기적계산효솔，명현감소료무효시극점용신도적시간，RFID계통탄토솔가제고도52％이상。
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% .
