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关键词： 射频识别   信息收集   目标标签   时间高效  

摘要： 随着RFID技术的不断发展和应用规模的扩大,传统的信息收集协议已无法满足一些高实时性应用的需求。例如,在冷藏仓库管理系统中,需要实时读取带有传感器的标签所收集的数据。然而,仓库中的普通标签也有可能响应阅读器的指令,与带传感器标签发送的信号产生冲突,影响阅读器对带传感器标签信息的收集效率。因此,如何高效地收集目标标签的信息成为一个具有挑战性的问题。为了满足小规模单阅读器RFID系统和大规模多阅读器RFID系统对目标标签信息收集的需求,本文通过对PIC协议和BIC协议的改进,提出了两种目标标签信息收集协议,以提高目标标签信息的收集效率并适应不同规模应用的需求。主要内容如下: (1)针对现有单阅读器目标标签信息收集协议中,存在单比特分配向量的分配效率低和轮询非目标标签ID导致数据发送量大的问题,提出一种增强型基于完美哈希的信息收集协议(E-PIC)。在原有协议的分配阶段中,通过构造双比特分配向量,使阅读器每轮广播的分配向量都能为更多目标标签安排在收集阶段的响应顺序,防止收集目标标签信息时发生冲突,同时停用部分非目标标签,减少后续阶段的时间开销。在轮询阶段,阅读器首先找出未被最小完美哈希过滤器停用的非目标标签,通过广播相邻两个非目标标签所在时隙索引的差值,以及下一个时隙中目标标签的确认值,停用分配到该时隙的非目标标签。相较于发送非目标标签的96位ID,发送间隔与确认值所需要的时间更少。仿真结果显示,比起现有的PIC协议,所提出的方法能降低3%的执行时间。 (2)针对现有多阅读器目标标签信息收集协议中,由于无法快速确认阅读器本地标签ID而导致时隙利用率低的问题,或因收集少量非目标标签信息产生额外时间开销的问题,提出了一种基于本地标签应答的布隆-完美哈希信息收集协议(BPIC)。阅读器通过接收本地标签的应答信号,并根据信道内的载波情况,构造一个布隆过滤器,用于确定位于其信号范围内所有标签的ID,防止因频繁查询非本地标签而出现大量空时隙,提高时隙利用率。然后,通过E-PIC协议为所有本地标签中的目标标签安排唯一的响应顺序,并停用所有非目标标签,以提高本地目标标签信息的收集效率。仿真结果显示,相较于现有E-TIC与Loc P协议,所提出的方法能减少10%以上的执行时间。

关键词： Energy harvesting  

摘要： We propose a new dual-band passive RFID tag antenna design by combining a rectangular spiral coil and patch-meander-line dipole with an interconnected structure. This design enables operation in high-frequency (HF) and ultra-high-frequency (UHF) RFID systems, suitable for energy harvesting and tracking applications. The simulations by the CST full-wave software demonstrate conjugate impedance matching between the tag antenna and two RFID tag chips. At 13.56 MHz (HF), the tag antenna exhibits an inductive reactance of 422.79 Ω, while at 922.5 MHz (UHF), it presents an impedance of 9 41 + j174 96 Ω. The antenna generates a maximum magnetic field intensity of 0.5 A/m and omnidirectional electromagnetic fields with an antenna realized gain of -4.26 dBi at 922.5 MHz. We also analyze the impact of the tag antenna combination using numerical software. Furthermore, we fabricate a prototype tag antenna and validate its performance with RFID readers. The proposed tag antenna achieves the maximum read ranges of 11 cm and 6.9 m for the HF (13.56 MHz) and UHF (920-925 MHz) bands, respectively, accompanied by the energy harvesting of 1.48 volts at the HF band by the coupling magnetic field received by the HF antenna to the chip ST25DV04K at the output voltage pin. © 2024 Supakit Kawdungta et al.

关键词： RFID   FSA   FSA   matrix pencil method   matrix pencil method   collision recovery   collision recovery   backscatter Rayleigh   backscatter Rayleigh   backscatter Rayleigh  

摘要： Collision recovery is considered one of the main potentials for improving bulk reading speed in the UHF radio identification (RFID) system. The collision occurs when two or more tags reply at the same time. State-of-the-art collision recovery algorithms rely on perfect channel state information (CSI), which is unrealistic. Moreover, these algorithms neglect the rate tolerance, that is, the uncertainty in the bit rate of the tag responses. This paper presents a novel algorithm to estimate all tag parameters, such as tag data rate, number of tags per slot, and CSI, using the Matrix Pencil Method (MPM). The proposed system is compatible with the existing EPCglobal Class-1 Gen-2 RFID standard. The accuracy of the proposed algorithm is evaluated with the different encoding schemes of the tag. The estimated parameters are forwarded to MIMO linear receivers to recover the colliding slots to speed up the identification process. The performance of the three linear receivers;Zero Forcing (ZF), Minimum Mean Square Error (MMSE), and Maximum Likelihood (ML) receivers, is evaluated when the CSI is estimated using the proposed algorithm. All receivers perform similarly due to their different sensitivity to the CSI estimation error. The proposed collision recovery system reduces the time for reading a bulk by at least 13% compared to the literature.

关键词： Radiofrequency identification   Location awareness   Convolutional neural networks   Neurons   Biological neural networks   Activity recognition   Neural networks   Machine learning   Data models   Recurrent neural networks   RFID   localization   activity recognition   convolutional neural networks  

摘要： As Radio Frequency Identification (RFID) methods continue to evolve to higher levels of complexity, one form of machine learning is making its appearance. The use of Neural Networks (NN) in the RFID field is steadily increasing, and in the fields of localization and activity recognition, promising results are being shown from a variety of research. RFID applications fall primarily under two types of problems including regression and classification. We analyze RIFD localization techniques which fall under regression, and activity recognition which falls under classification. Many works don't classify themselves as activity recognition methods, but because they fall under the classification category, we still consider them as activity recognition techniques. This research overviews the Neural Network models in the localization field based on whether they can perform independently of the environment in which they were tested. For activity recognition and accessory fields, the major methods involve tag-based and tag-free approaches. After the models are surveyed, a comparison study is given to examine what may be the cause for increased accuracy between different Neural Network models.

关键词： Special issues and sections   Antennas   Radiofrequency identification   Internet of Things   Inventory management   Fourth Industrial Revolution   RFID tags   Design engineering  

摘要： The RFID community is enjoying new impetus coming from the revolutionary Internet-of-Things (IoT) paradigm and its integration with new application scenarios like Industry 4.0. RFID technology, in fact, enables reliable communication at low cost and with lightweight apparatus, desirable features for pervasive devices employment as desired by the IoT. Nonetheless, commercial-off-the-shelf (COTS) solutions cannot be always employed in some of emerging application scenarios, requiring customized reader and/or tag antenna design. In order to collect the most recent developments in the antenna design research for both legacy and novel RFID application contexts, the IEEE Journal of Radio Frequency Identification proposed the special issue "Advanced Antennas for Radio Frequency Identification (RFID) Systems". A RFID system and its performance clearly depend on the antenna ability, both on reader and tag sides, to make the system accessible from short or long distances, and on different environments. The latter is particularly important in the new RFID tag application contexts, e.g., industrial manufacturing processes, vehicular environments, etc., where tags are indifferently applied on heterogeneous materials, many times on metal surfaces, and for this reason the antenna design requires particular care. Moreover, the pervasive diffusion of RFID-IoT devices poses new challenges in inventory assessment, requiring even longer read ranges and wide coverage ability, which clearly translates in new reader/tag antenna requirements. The purpose of this special issue was therefore to encourage the research on novel RFID antenna design solutions for both reader and tag devices to face these new application scenarios and cope with the new challenging requirements. Starting from magnetic coupling resonant high-frequency (HF) RFID systems, Mukherjee et al. consider the annoying problem of HF RFID reading performance deterioration in the presence of metallic conductors in the close vic

关键词： 射频识别   未知标签检测   位掩码   时间性能  

摘要： 随着射频识别(RFID)技术的进步,过去十几年间,该技术已经不只具有简单的标签识别功能。目前,RFID技术的研究已拓展至未知标签的检测与识别、丢失标签的追踪、标签基数估计和标签定位等方面。 本文致力于解决一个关键问题:如何有效地发现未知标签的存在。未知标签是指那些存在于阅读器覆盖范围内,但未被记录在后台数据库中的标签。大量未知标签的出现可能会对其他贴有标签的物体造成重大风险和经济损失。例如:带有放射性的化学物质错误地存放在了其它化学品仓库中,可能会引发辐射污染或危险的化学反应,导致灾难性后果或巨大的财产损失。针对这类现实挑战,RFID技术在检测未知标签方面具备显著功能优势。 现有的未知标签检测协议主要依赖于多Hash函数和Bloom过滤器,但这种方法要求标签存储Hash种子和执行多重Hash运算,导致标签的硬件成本增加。此外,现有协议在时间效率方面仍有提升的潜力。因此,本文提出了一种基于Select指令的未知标签检测协议,以解决实际环境中因未知标签存在而可能引发的问题。该协议分为两个阶段:位掩码选择阶段和标签检测阶段。在位掩码选择阶段,利用位掩码选择算法确定用于发现未知标签的位掩码。本文还提出了三种适用于不同环境的位掩码选择算法,分别是标准型、快速型和稳定型。在标签检测阶段,阅读器向标签广播前一阶段确定的未知标签位掩码,以判断其覆盖区域内是否存在未知标签。 本研究从理论上分析了提出的协议和位掩码选择算法,并优化了相关参数,以提升检测性能。此外,通过一系列广泛的仿真实验和对比实验,验证了本协议的高效性。实验结果证明,本文提出的协议能够高效地解决未知标签检测问题。

摘要： Recently, the 5th Io T Industry Development and Technology Cooperation Seminar in 2023 was held in Xi’an, Shaanxi *** on the industrial progress and trend of 5G Internet of Things (Io T), radio frequency identification (RFID), passive Io T and other issues, the attendees discussed new technologies, new application and development trends of Io T, to accelerate the integration and large-scale application of Io T industry.

关键词： RFID   guidance   tracking   blind   RFID-lanes   particle filter   phase   portable reader  

摘要： In this paper, we investigate the possibility of using RFID technology for navigation and guidance within lanes. The lanes consist of RFID tags, placed on the floor. The tags represent unique spatial identifiers. By processing phase-measurements from such tags, a user, carrying an RFID reader, can be ${i}$ ) kept within the lane, ii) guided to the desired destination and iii) tracked in real time. Two properties are exploited for lane-keeping: the measured Rate-Of-Change (ROC) of the phase measurements per tag and the number of readings per tag within given time-periods. Thanks to these properties, an indicator function estimates the pose of the agent within the lane and gives auditory and visual feedback when one approaches the boundaries of the lane. Localization and tracking is accomplished separately by feeding phase-ROC measurements in a particle filter. Robustness of the proposed method is verified by measurements presented herein.