大规模RFID系统中未知标签的快速可靠识别

Fast and Reliable Unknown Tag Identification for Large-Scale RFID System

未知标签的存在可能会给供应链系统、仓储管理等带来不可忽略的经济损失或安全隐患,因此未知标签的识别研究对射频识别系统意义重大。为减少冲突时隙的比例,传统协议通常需要设置较大的帧长,导致对未知标签识别效率较低,且协议中大多存在冲突时隙被直接废弃、时隙利用率低的问题。提出冲突分解法(CRM)协议,通过把大部分的冲突时隙转变为有用时隙,将没有未知标签参与的冲突时隙内已知标签灭活,对有未知标签参与的冲突时隙进行区分码的解缠绕,以提取并识别冲突时隙中的未知标签。通过优化帧长设置,提高时隙利用率,增大已知标签的灭活效率及未知标签的识别效率。实验结果表明,CRM协议对未知标签的识别效率分别可达到UTI-SBF、HUTI、PTI、FUTI协议的2.5、2.2、1.4、1.5倍。

The presence of unknown tags may result in economic losses and security issues in supply chain and warehouse management.Thus,study on unknown tag identification is important in Radio Frequency Identification(RFID)system.To decrease the proportion of collision slots in a time frame,traditional protocols adopt a large time frame size;however,it reduces the time efficiency.In most of the existing unknown tag identification protocols,the collision slots are abandoned straightforwardly;therefore,the slot utilization is low.A Conflict Resolution Method(CRM)protocol is proposed in this paper,it can transform most of the collision slots into useful slots;the known tags map into a collision slot,in which there are no unknown tags,can be inactivated directly,and the unknown tags can be extracted through distinguishing code in collision slots when the unknown tags are existing.By optimizing the frame length setting,the time slot utilization is improved,and the inactivation efficiency of known tags and recognition efficiency of unknown tags are improved.The experimental results show that the recognition efficiency of CRM protocol for unknown tags is 2.5,2.2,1.4,and 1.5 times of UTI-SBF,HUTI,PTI,and FUTI protocols respectively.