摘要： 针对最大帧长度受限情况下射频识别中的标签碰撞问题,提出分组部分时隙帧预测ALOHA 算法。通过分组操作,限定每次待识别标签数在最大帧长的有效识别范围内。采用部分时隙帧预测,若部分时隙的碰撞或空闲比例超过门限值,则立即调整帧长,从而减少使用的时隙数。实验结果表明,该算法能有效降低使用的时隙数,提高系统识别效率,在标签大量动态变化的情况下,平均识别率可达35． 58% ,具有良好的适用性。
关键词:
射频识别,
防碰撞,
动态帧时隙ALOHA,
部分时隙,
随机数
Abstract: To solve the tags collision problem in Radio Frequency Identification(RFID) system where the maximum
size of frame is limited, this paper proposes a new Grouping Part time Slot frame Prediction ALOHA ( GPSPA ) algorithm. Tags are divided into smaller groups considering the limited frame size’ s capability. Part slots prediction scheme is used in identification to decide whether to change the frame size immediately. If the empty or collision slots percentage exceeds the threshold value,the frame size is changed promptly. Simulation results show that the proposed algorithm can increase the system efficiency and consume fewer slots than previous work. Besides,the influence of the parameters of the algorithm is discussed by simulation tests. The system identification efficiency can maintain 35. 58% , approximating to the limit value,where dynamic tags are changing greatly. The proposed algorithm provides a good solution for RFID systems where the tags are changing within a wide range and the frame size is limited.
Key words:
Radio Frequency Identification (RFID),
anti-collision,
Dynamic Framed Slotted ALOHA (DFSA),
part
time slot,
random number
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