共查询到20条相似文献,搜索用时 46 毫秒
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在被动式射频识别(Radio frequency identification,RFID)系统中,即使有多个标签同时向阅读器发送信息,捕获效应也能使其中一个标签被阅读器成功识别. 而且,捕获效应还会导致标签漏读.为防止标签漏读和进一步提高捕获效应下的识别效率,我们提出一种新的防冲突协议,该协议采用自适应和分配技术来减少标签间冲突.其优点在于,可合理地分配冲突标签和隐藏标签,从而提高识别效率. 计算机仿真结果显示,在捕获效应发生的环境下,本文协议的识别效率优于现存协议. 相似文献
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Lehto A. Nummela J. Ukkonen L. Sydanheimo L. Kivikoski M. 《Automation Science and Engineering, IEEE Transactions on》2009,6(1):66-79
Radio frequency identification (RFID) systems for the paper industry is an emerging research topic due to the need for an automated identification system for the paper industry which would carry on the identification codes of paper and board reels throughout their life cycle. This paper discusses the application of passive ultra-high frequency (UHF) RFID systems to the paper industry. Challenges, benefits, and the application environment of using passive UHF RFID systems in the paper industry are presented and discussed. The major challenges are development of globally operable tag antenna designs and integration of reader units and reader antennas to paper handling machinery. To confront and solve these challenges, this paper presents novel tag antenna designs for paper and board reel identification and proposes solutions for reader and reader antenna integration to paper handling machinery. In addition, the identification locations within the paper reel supply chain and the effects of RFID systems to supply chain visibility are presented and discussed. In addition, test results of using passive UHF RFID systems in the paper industry environment are presented. 相似文献
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基于RCS的无源超高频RFID标签识别距离研究* 总被引:1,自引:0,他引:1
通过对无源超高频RFID系统中标签功率的获取、传递以及反射的研究,提出了一种基于雷达散射截面(RCS)对标签识别距离进行计算的新方法。采用高频电磁场仿真软件FEKO对不同标签天线进行建模与仿真,计算标签天线在不同负载下的RCS;再结合识别距离表达式计算该标签的最大识别距离,与标签已有的实测参数进行比较,计算结果与实际参数吻合。研究结果证实了该方法对研究标签识别性能具有很好的借鉴意义。 相似文献
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射频识别技术(RFID)在超高频段的应用将成为物流商业开发的主流,对于排除阅读器识别多个电子标签发回信号的电磁波干扰,实现快速、准确地信息识别,抗碰撞的搜索算法是最为关键的因素.研究了基于广度优先动态二进制搜索算法,并进一步提出优化方案,从技术上切实提高了射频识别系统的效率. 相似文献
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无线识别感知平台(Wireless Identification and Sensing Platform,WISP)可以从RFID(Radio Frequency Identification)阅读器发射的超高频信号中获取能量,为其内置低功耗微控制器和传感器供电,将传感器采集的数据传递到阅读器。提出基于否定应答(Negative Acknowledgement,NAK)的数据传输方案,可以克服WISP因传递的数据包重复比率太高而浪费信道这一弊端。实验结果表明:所提方案可以有效地降低数据包的重复比率,提高有效吞吐率。 相似文献
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针对自由空间模型在预测射频识别系统识别距离时存在的偏差,综合考虑射频识别系统应用的多径传播环境,建立一种无源超高频射频识别系统电波传播模型,并重点分析了前向链路路径损耗的主要影响因素及其计算方法。基于该电波传播模型,探索性地提出实际环境下的无源超高频射频识别应用模拟思路。仿真和测量结果表明,该模型在预测无源超高频射频识别系统识别距离时更为准确。 相似文献
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采用ARM9微处理器为主控制器,射频处理采用奥地利微电子公司的AS3992芯片为核心,设计开发了超高频RFID读写器系统。系统设计了外置功率放大电路、功率探测电路和天线端阻抗匹配调谐电路,使发射机输出功率达到+33dBm,并有效地提高了接收机信噪比,实现了对符合ISO/IEC 18000-6C 900MHz RFID协议的多标签的稳定高速读写;同时在ARM9硬件平台上移植了嵌入式Linux系统,并设计了读写器Web固件控制系统,以实现多标签盘存和读写器的网络配置等操作,为读卡器之间数据通信和二次开发提供平台。该系统已搭建运行于某电厂运煤车辆出入RFID管理控制系统中,运行结果表明,系统最大稳定读取距离达到10m,满足了工程需求。 相似文献
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针对频率范围在860~960 MHz内的超高频(UHF)射频信号,提出一种基于独立成分分析(ICA)和帧时隙的射频识别(RFID)系统防碰撞算法。通过合理的帧时隙数选择可以使每一时隙内的标签数不大于阅读器的天线数,从而可以利用ICA算法实现多标签的同时识别。仿真结果表明,与传统的标签防碰撞算法及基于位隙动态分组的盲分离多标签防碰撞算法(BSDBG)相比,该算法在标签识别率方面具有明显的优势,且随着天线数的增加,算法的识别时间要低于BSDBG算法,进一步验证了将盲源分离技术运用于标签识别的可行性和高效性,在需要高效率和智能化管理的工程领域中具有潜在的应用价值。 相似文献
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Yanis Merakeb Hussein Ezzeddine Julien Huillery Arnaud Brard Rachida Touhami Yvan Duroc 《国际射频与微波计算机辅助工程杂志》2020,30(10)
The article presents an experimental platform, so called “RFID Waveformer,” dedicated to the study of waveform optimization in the radio frequency identification (RFID) context. It is a flexible solution that enables waveform design and their energetic performance evaluation in a ultra high frequency (UHF) RFID link following the ISO‐18000 GEN2 standard protocol. It consists of a reader emulated by a LabVIEW interface controlling radiofrequency laboratory instruments, which perform real time tag response detection. Its interconnection with MATLAB routines enables the design and the evaluation of arbitrarily shaped RFID waveforms. In this article, for illustration, three waveforms are tested with RFID Waveformer in a complex propagation environment: pulsed wave (PW) and time reversal (TR) modes compared to the traditional continuous wave (CW) mode. Experimental results show that both PW and TR modes improve the energetic efficiency of the forward link and so the RFID read range compared to CW mode. Furthermore, TR presents the optimal efficiency in complex propagation medium. The RFID Waveformer enables tag response detection in the three modes offering ease of use and repeatability of measurements. The RFID Waveformer being not limited to the scenario considered in this article, it is a versatile solution extendable to other contexts. 相似文献
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Radio-frequency identification (RFID) tags have found their way into many applications. When tags implement cryptographic algorithms, side-channel analysis (SCA) attacks become a concern. Especially tags in the ultra-high frequency (UHF) range are susceptible to so-called parasitic-backscatter attacks that can be applied from a distance. Whereas it is known that such attacks are a threat for passive low-cost tags, no results are so far available for sensor-enabled tags. In this work, we evaluate the parasitic backscatter of wireless identification and sensing platform (WISP) tags by conducting differential electromagnetic analysis (DEMA) attacks. We apply the attacks on a passively as well as a semi-passively operated WISP tag from a distance of 30 cm and compare the results with an attack on a commercial low-cost tag. The results show that the evaluated WISP tags are less susceptible to DEMA attacks based on the parasitic backscatter than the evaluated commercial low-cost tag. Moreover, we present a measurement approach that allows to detect the weak parasitic backscatter modulated on the strong reader field without the need for an expensive hardware receiver or a dedicated demodulation circuit. 相似文献
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在射频识别技术RFID(Radio Frequency Identification)技术的应用中,不同阅读器的信号之间互相干扰造成的阅读器冲突问题是制约系统性能的主要瓶颈之一,尤其在阅读器密集分布和移动的环境中,问题更为突出。结合现有多种抗冲突方法的优点,提出一种针对多信道的、阅读器密集分布的RFID系统的基于IRCM的抗冲突协议。仿真表明在多信道、阅读器密集分布的RFID系统中该协议能显著提高系统效率。 相似文献
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针对在高度密集的射频识别(RFID)系统中因标签碰撞导致系统识别效率降低的问题,提出了一种锁位式双前缀探针防碰撞算法。新算法在双前缀探针算法的基础上,利用曼彻斯特编码特点,通过锁位指令锁定碰撞位,提取碰撞信息,并且在后续的识别过程中仅传输这部分信息,结合双前缀查询思想,在减少碰撞时隙的同时,减少了数据传输量。算法在设计的过程中充分考虑了总时隙数、吞吐率、识别效率这三个重要的性能指标。理论和仿真分析表明,相对于已有算法,新算法具有更高的识别效率和吞吐率,更适合RFID识别系统。 相似文献
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