射频识别系统多标签防碰撞算法

Multi-tags anti-colision algorithms in RFID system

为提升射频识别(RFID)系统中单阅读器多标签环境的识别效率,给出一种在标签编码前缀相同条件下使用的混合算法。先通过Q算法调整帧长,使之与待识别标签总数近似相等,以达到最大识别效率,并给未识别的碰撞标签标记分组号,再对已分组的碰撞标签使用反向查询树算法(QTR)一一识别。根据EPC C1G1标准,在单阅读器多标签的系统环境下,选取标签编码长度为96位,分别在标签编码完全随机与标签编码前60位相同两种情况下进行仿真,结果表明在标签编码前缀相同时,较之QT算法、Q算法,混合算法可提高系统吞吐率,降低阅读器发送总时隙数。

In order to improve the effciency of single reader under multi-tags RFID system, a hy- brid algorithm is proposed to use in a particular condition which tags number have the same pre- fix. In the first step of this algorithm, the Adaptive Slot-Count （Q） algorithm is used to adjust the frame size to approach the number of tags to achieve maximum efficiency and divide the colli- sion tags into group. In the second step, the Query Tree with Reversed IDs （QTR） is used to i- dentify collision tags grouop by group. According to EPC C1G1 Standrad, in the single reader and mulit-tags system enviroment, simulation is carried out with the size of tag number of 96 in two cases： complete random and same prefix of tag number. Result show when the tags number has a same prefix, compared to QT and Q algorithm, the hybrid algorithm could improve the throught rate and reduce the number of slots.