CAJ | 학술논문

现有 RFID 系统的 QT 算法在电子标签数量和密度增加及 EPC 较长时会造成查询次数过多、碰撞次数增加、系统效率低等问题．针对 QT 算法的缺点，提出了改进型的跨层查询算法，包括 SQT 算法和MQSQT 算法．SQT 算法通过改进 QT 算法将查询电子标签位元串方式改为跨层查询方式，MQSQT 算法通过询问 EPC 字串的下2个位元值并进行异或逻辑运算，以求出包含跨层查询所必需的字串最小集合．仿真结果表明改进型算法减少了碰撞次数，平均查询次数有较大改善，提高了 RFID 系统的效率．
현유 RFID 계통적 QT 산법재전자표첨수량화밀도증가급 EPC 교장시회조성사순차수과다、팽당차수증가、계통효솔저등문제．침대 QT 산법적결점，제출료개진형적과층사순산법，포괄 SQT 산법화MQSQT 산법．SQT 산법통과개진 QT 산법장사순전자표첨위원천방식개위과층사순방식，MQSQT 산법통과순문 EPC 자천적하2개위원치병진행이혹라집운산，이구출포함과층사순소필수적자천최소집합．방진결과표명개진형산법감소료팽당차수，평균사순차수유교대개선，제고료 RFID 계통적효솔．
QT algorithm of current RFID system could result in increased query numbers,high collision frequency and low efficiency of the system when the number and density of EPC electronic label increase.In allusion to these shortcomings,this paper proposed a cross layer algorithm,including the SQT algorithm and MQSQT algorithm.SQT algorithm became cross layer query mode through im-proving the bit string mode of QT algorithm querying for electronic tag,and MQSQT algorithm conducted XOR logic operation based on 2 bits of EPC string of current query,so as to find the minimal set of query string needed for the cross layer search.The simulation re-sults showed that the improved algorithm reduced the number of collisions,average numbers of queries had been greatly improved,and it improved the efficiency of RFID system.