冲突射频识别标签分离的似然解码  

Likelihood Decoding for Collision Radio Frequency Identification Tags Separation

作　　者：桂妮霞 吴海锋[1,2] 李毅 曾玉 陈跃斌[1] GUI Nixia;WU Haifeng;LI Yi;ZENG Yu;CHEN Yuebin(School of Electrical and Information Technology,Yunnan Minzu University,Kunming Yunnan 650500,China;Yunnan University Intelligent Sensor Network and Information System Technology Innovation Team,Kunming Yunnan 650500,China)

机构地区：[1]云南民族大学电气信息工程学院,云南昆明650500 [2]云南省高校智能传感网络及信息系统科技创新团队,云南昆明650500

出　　处：《传感技术学报》2022年第5期635-643,共9页Chinese Journal of Sensors and Actuators

基　　金：国家自然科学基金项目(62161052);云南省重点应用和基础研究基金项目(2018FA036);云南省教育厅科学研究基金项目(2021Y655)。

摘　　要：在超高频(Ultra High Frequency,UHF)无线射频识别(Radio Frequency Identification,RFID)系统中,当多个标签同时向阅读器发送数据就会发生标签冲突,在介质访问控制(Media Access Control,MAC)层防冲突效率较低,采用物理层分离解码算法可有效提高该系统的吞吐量。特别地,由于Miller码拥有比FM0码更多的副载波,具有更高的抗噪声性能,因此提出了一种物理层分离的最大似然Miller解码方法,用于优化传统Miller解码。该方法聚类并确定各簇对应标签排列情况以分离标签信号,再用最大似然的Viterbi解码完成冲突信号的识别。实验中,仿真数据结果表明,该算法在低信噪比下,分离效率高于传统解码方法约20%;实测数据结果表明,该算法嵌入至动态帧ALOHA系统中,吞吐量达到0.55,高于传统理论最优值0.37。In Ultra High Frequency(UHF)Radio Frequency Identification(RFID)systems,when multiple tags send data to the reader at the same time,tag conflicts will occur.The conflict prevention efficiency is low in Media Access Control(MAC)layer.Physical layer separation decoding can improve the throughput of the system.In particular,Miller code has more subcarriers than FM0 code and thus has a higher anti-noise performance.For this reason,a maximum likelihood Miller decoding method with physical-layer separation is proposed to optimize traditional Miller decoding.Cluster analysis is performed to determine the corresponding label arrangement of each cluster,and separate the label signal,then maximum likelihood Viterbi decoding is used to complete the identification of the conflict signal.In the experiment,the simulated results show that the separation efficiency of the proposed algorithm is about 20%higher than that of traditional decoding methods at low SNR.The measured results show that the throughput of a RFIO dynamic trame ALOHA system embedded with the proposed algorithm arrives at 0.55,which is higher than the theoretical optimal value of 0.37.

关 键 词：射频识别 物理层防冲突 VITERBI算法 Miller码 标签冲突 

分 类 号：TP391.4[自动化与计算机技术—计算机应用技术]