Abstract: To address the problem that the efficiency of stochastic ALOHA is very low and deterministic tree searching algorithm has the limitation that the number of the tags in the area doesn’t change, this paper presents an improved quadtree RFID anti-collision algorithm. The tags in reading range of reader modify their responsive probabilities for grouping according to different inquiry commands. Reader uses the quadtree RFID anti-collision algorithm by comparing collision bit to identify a tag whose responsive probability is one. Formula deduction proves the rationality of the algorithm using quadtree recognition. Examples and simulation results show the algorithm can reduce the number of queries and the communication volume between readers and tags, the recognition efficiency of reader is effectively promoted.

Key words: Radio Frequency Identification（RFID）, anti-collision algorithm, responsive probability

摘要： 针对随机ALOHA算法效率较低，确定性树型方法要求区域内标签数量不变的问题，提出一种改进的四叉树RFID防碰撞算法。在阅读器阅读范围内的标签根据不同的问询命令修改自身应答概率进行分组。阅读器采用比较碰撞位的四叉树算法识别应答概率为1的标签。通过公式推导证明了算法采用四叉树识别的合理性。实例说明和仿真结果显示，该算法能减少阅读器和标签之间的查询次数和通信量，有效提高阅读器的识别效率。

关键词: 射频识别, 防碰撞算法, 应答概率