一种改进的混合查询树防碰撞算法

An Improved Anti-collision Algorithm Based on Hybrid Query Tree

针对射频系统中混合查询树算法产生的问询前缀与空闲时隙数多的问题,提出了一种改进的混合查询树算法.该算法首先对标签信息进行一次预处理;然后利用标签信息中"1"的奇偶数对其进行分组;符合查询前缀的标签统计除去前缀的后两位信息中"1"的个数,并决定其推迟几个时隙进行响应.性能分析结果表明,改进的算法与混合查询树算法相比,减少了问询前缀数、空闲时隙数以及平均时延,识别效率明显提高.

To resolve the problem of the HQT algorithm produces much query prefix and idle time slots in the RFID system, an im- proved HQT algorithm was proposed. The new algorithm has some enhancing as follows：firstly, make a preprocessing to information of tags;secondly,group tags based on the parity of “1” in the information of tags;lastly,the tag which matches prefix sent by reader delays slots depending on their count of value 1 of upper 2 bit. The performance shows that the algorithm reduce the number of query prefix,idle time slots and average identification delay and has more advantages in effectiveness of identifying than HQT algorithm.