一种改进的自适应多叉树防碰撞算法

Enhanced Adaptive Division Anti-collision Algorithm

针对传统自适应多叉树防碰撞算法在标签识别过程中存在的空闲时隙过多、阅读器与电子标签间的通信负载量过大等不足,提出了一种改进的自适应多叉树防碰撞算法(Improved Adaptive division Collision Tree algorithm,IACT)。该算法通过计算碰撞因子决定采用二叉树或四叉树。当采用二叉树时,若阅读器检测到碰撞位只有一位,则无需再次发送命令即可以直接识别出标签;采用四叉树时,阅读器首先发送一命令,要求标签返回最高两个碰撞位对应的编码,然后根据编码得到碰撞信息。在标签中加入计数器,使用最高两个碰撞位和计数器值作为查询命令,响应的电子标签将序列号的后缀信息发送给阅读器处理。算法性能分析和实验仿真表明,IACT算法能有效减少系统总时隙,降低了通信负载开销,提高了标签识别效率。

Aiming at the disadvantages of the traditional adaptive division collision tree algorithm in the process of tag identification such as many idle time slots,large communication overhead between the reader and tags,this paper pre-sented an improved adaptive division collision tree algorithm(IACT).The algorithm determines the adoption of the binary-tree or quad-tree by calculating collision factor.As for the binary-tree,if the collision-bit is only one,tags can be identified directly without sending commands again.As for the quad-tree,reader first sends a command for tags to return the corresponding coding of the highest two collision bits,and obtains collision information through encoding.The reader takes the value of counter and the highest two collision bits as the parameter of query command by using the counter,and tags only send the postfix of ID to the reader.The performance analysis and simulation results show that IACT algorithm can effectively reduce the total timeslot consumption and the communication load,and improve the re-cognition efficiency as well.