射频识别(radio frequency identification,RFID)是物联网需要研究的关键技术之一.基于对RFID技术的研究,提出了一种基于关联ID的防碰撞新方法.有记忆标签和无记忆标签在防碰撞算法上的主要区别在于二者实现的机理有所不同.针对有记忆的标签,该方法增加标签之间的关联关系,使标签在一定的触发条件下可以主动发送自己的ID.该方法不同于无记忆的标签.由于父子标签间存在关联关系,将该方法应用于基于多叉搜索树的确定性防碰撞情况中,其优势是单次通信可以同时识别多个标签,极大地提高了识别效率;将该方法应用于不确定性的ALOHA防碰撞情况中,读写器可以依据脉冲的位置判断出空时隙的位置,从而避免由于(在读取时隙时)读取空时隙而造成的效率下降问题.由于该方法不受ID的长度限制,通过大量的实验表明,该方法在多种应用过程中能够大幅降低碰撞的概率,能够提高系统的识别效率.
The RFID technology is one of the key technologies of the Internet of things which need to be studied.Based on our researches of the RFID technologies,a kind of new anti-collision approach based on AID(associated ID)has been put forward in this paper.As we know,the realization mechanism of anti-collision approach is between the tags with the memory and the memory-less tags.We propose a method to build the association between tags with memory,so that tags in a certain trigger condition can take the initiative to send their own ID.Tags use modulated binary pulse to send data to the reader.This approach is different from that with the memory-less tags.Because there exists association relationship between father-tag and son-tag,when it is applied to the multi-tree searching method that we have proposed,the advantage of this method is that a single communication can identify multiple tags at one time,which has greatly improved the identification efficiency.When the approach is applied to the uncertainty ALOHA algorithm,the reader can decide the location of the empty slots based on the position of the binary pulse,so the working reader can avoid the efficiency decreasing problem caused by reading empty slots.Due to no limit of ID length,experimental results of our simulations show that this approach can greatly decrease the probability of collision and improve the identification efficiency of the system during many kinds of its applications.