Abstract: In RFID system, the collision will occur while a reader attempts to identify multiple tags at the same time. The anti-collision algorithm is necessary. For tag-collision problem of radio frequency identification system, a stable and efficient anti-collision protocol is very significant. In this paper, a new bit-conversion anti-collision algorithm based on slotted binary tree for RFID is proposed. First, it converts the original ID of the tag. Then, based on the different number of bits in different slots, the tag will respond to reader’s request. By using Manchester code, the sent information of all the tags will be identified in much shorter time. Compared with other search algorithms, mathematics analysis and simulation results show that the algorithm reduces the times of the reader’s request and significantly improves recognition efficiency.

Key words: bit-conversion, anti-collision, Radio Frequency Identification（RFID）, tag, slots

摘要： 在射频识别系统中，当多个标签同时响应阅读器的请求时，就会发生碰撞。对射频识别系统中多标签的碰撞问题，提出了一种基于比特转换的时隙二叉树RFID标签防碰撞算法。通过该算法，首先将标签ID进行比特转换，然后根据转换后比特位数的不同分时隙响应阅读器的查询请求，最后，利用曼彻斯特编码原则判断出标签发送的比特信息。通过数学分析和仿真结果表明，此算法与其他搜索算法比较，减少了阅读器的查询次数同时可以大大降低识别时间，并且可以显著增加系统吞吐量。

关键词: 比特转换, 防碰撞, 射频识别, 标签, 时隙