Abstract: For practical application, the tags of Radio Frequency Identification (RFID) system are often moving. An RFID system on a conveyor belt was analyzed and simulated using Matlab. The result showed that if the tag density on the conveyor belt D and the conveyor belt speed V were constant, the identification rate became the maximum when the frame size N was equal to the number of unidentified tags n. When the slot duration was constant, the identification rate was only relative with D and V, and would not be affected by the conveyor belt length L in reader's coverage. Meanwhile, the existing tag estimation methods were amended according to the model of conveyor belt and a new estimation method was proposed, which significantly improved the precision in the case of large number of tags compared to other estimating methods.

Key words: anti-collision, Radio Frequency Identification (RFID), moving tag, tag estimation, ALOHA algorithm

摘要： 针对现实应用中标签经常处于运动状态的情况，对传送带模型下的无线射频识别(RFID)系统进行了分析,并使用Matlab做了相应的仿真实验。结果证明，当标签密度D与传送带速度V保持不变时，识别率P在帧长度N与作用范围内未识别标签数n相等时最高。当时隙持续时间一定时，识别率P只与V和D有关，而与作用区域内传送带长度L无关。同时针对该模型，对现有的标签估算方法进行了修正，在此基础上提出了一种新的估算方法，该方法的准确度在标签数目较大时有着明显的提高。

关键词: 反碰撞, 无线射频识别, 运动标签, 标签估算, ALOHA算法