共查询到20条相似文献,搜索用时 31 毫秒
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提出了一种基于智能手机音频接口的 UHF RFID读写系统解决方案,该方案采用 AS3992专用射频收发芯片,创新性地基于智能手机音频通信接口实现了对 RFID 读写器的控制。测试仿真结果表明,智能手机音频接口的 UHF RFID读写系统使用方便、便携性好,系统无需无线配对,数据实时传输可靠性高。 相似文献
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Sub-threshold leakage is a major issue for low power circuits design, especially for SRAM design in SoC. Sub-threshold leakage can be decreased by scaling down supply voltage. However, this may dramatically increase the circuit delay. In this paper, we propose a novel 6 T SRAM array structure with a switch module which operates in the near threshold region to reduce the leakage current. In order to verify our proposed leakage reduction scheme, we designed and simulated an 8192 kB SRAM array based on a 16 KB single port SRAM cell memory model in 55 nm process. Several 6 T SRAM Array instances are implemented in 55-nm 1P6M CMOS technology to measure the standby current of the proposed scheme as well. With the proposed technique~ we achieved 28.3% reduction for leakage current compared to traditional 6 T SRAM array, in standby mode where gate leakage is dominant. The total penalty is 2% area increase and 1% speed reduction. 相似文献
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A novel direct conversion receiver with low cost and low power is implemented in a 0.18 μm 1P6M standard CMOS process for a Mobile UHF RFID reader.A highly linear active mixer with low flicker noise and low noise active load is proposed.An efficient and low cost on-chip DC offset voltage canceling scheme is adopted with a high-input-impedance four-input OPAMP to buffer the output of the DC offset canceller(DCOC) block.The receiver has a measured input 1 dB compression point of 2 dBm and a sensitivity of 72 dBm in the presence of the large leakage signal from the transmitter.Only occupying a silicon area of 2.5 mm 2 and consuming 21 mA from a 1.8 V supply,the receiver makes the mobile UHF RFID reader to communicate with a transponder in a distance of 1 m conveniently. 相似文献
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无源UHF频段RFID技术信号传输速度快,覆盖距离远,通过与互联网、通讯等技术相结合,可实现全球范围内物品的跟踪与信息共享。该技术由射频模拟前端电路、控制逻辑电路等组成的无源UHF超高频射频识别标签系统,由外接天线与读写器完成通信,天线既要与识别标签相匹配,又要与读写器较好地通信,天线决定了标签是否能正常工作,同时也决定了信号传输的距离。为此,通过研究天线的匹配阻抗、形状尺寸与大小,以及频带的设计,探索出了低成本、高可靠的天线设计方案。 相似文献
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UHF RFID标签具有非光学可视阅读、感应距离远和读取速度快的特点.针对中小型仓储应用提出了UHF RFID标签可重用和UHF RFID阅读器软硬件定制的设计方案.UHF RFID阅读器硬件采用了Cortex- M3内核处理器LPC1768、UHF RFID模块读取标签、SPI Flash扩展存储和TFT LCD显示... 相似文献
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DONG JingJing ;JIANG HanJun ;ZHANG LingWei ;WEI JianJun ;LI FuLe ;ZHANG Chun ;WANG ZhiHua 《中国科学:信息科学(英文版)》2014,(10):209-218
A novel low-power DC offset calibration (DCOC) method independent of intermediate frequency (IF) gain for zero-IF receiver applications has been reported. The conventional analog DCOC method consumes greater power and affects the performance of the receiver. The conventional mixed-signal method requires enhanced memory to store the calibration results at different receiver gains as the DC offset is relative to the radio frequency (RF) and IF gain. A novel algorithm is presented to make the DCOC process independent of IF gain, which significantly reduces the memory area. With the proposed circuit, the receiver calibrates only once so settle-time and power consumption of the IF circuit is lowered. A DCOC circuit with the proposed method is manufactured in 0.18 p.m CMOS technology that drains nearly 0 mA equivalent current from a 1.8 V power supply. 相似文献
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As people own more and more various smart devices, providing advertising to those devices has become a lucrative platform for different advertisement providers. However, the way advertisements are delivered to customers' smart devices needs to be improved. Many variables determine the most effective way to provide the mobile advertisement to the end-user. So a mobile advertising service based on the 4R model is needed The correct time, location, contents and target device to make the mobile advertising interesting and also useful for the customers. need to be determined in order for the advertisement to be contextual and the most effective. The 4R model is beneficial for the advertisers and the end-users alike. 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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超高频RFID标签一致性的近场检测技术 总被引:1,自引:0,他引:1
超高频RFID标签一致性直接影响RFID系统中采集数据的识别率和准确率。采用接收信号强度指示RSSI(Received Signal Strength Indicator)技术及数理统计,采集标签反射信号强度,设定标准差阈值,作为标签一致性检测参数。研制弯折偶极子近场天线,实现0.1 mm近距离标签识读。利用屏蔽效应,在全自动卷筒式RFID标签套装上设置打点标识机构,对标签批量标记,可实现对柔性超高频RFID标签的高速、批量一致性检测。 相似文献
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超高频射频识别标签数据盲分离算法 总被引:1,自引:0,他引:1
提出了一种新的基于ICA的超高频(Ultra high frequency,UHF)射频识别(Radio frequency identification,RFID)多标签混合数据盲分离算法。在分析UHF RFID系统链路传输模型、标签数据编码规则以及多天线RFID系统模型的基础上,得出UHF RFID多标签混合数据符合ICA算法要求的结论,并利用FastICA算法对UHFRFID仿真数据进行了盲分离,定量分析了算法的分离效果及抗噪声性能。实验结果表明,利用ICA技术对多标签混合数据进行盲分离可获得良好的效果。这为将盲分离技术应用于UHF RFID系统标签防碰撞算法奠定了良好的理论和实验依据。 相似文献
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Castillo S. Aris L. Clunie Gisela Riley Jeanette 《通讯和计算机》2014,(3):305-311
This paper presents use cases developed for a mobile learning application named MLEA (mobile learning environment adapter), developed in collaboration with the Universidad do Vale do Rio dos Sinos-Unisinos, Brazil and UTP (Universidad Tecnologica de Panama). MLEA allows users to access, through a single platform, courses in a content management system--Moodle. The objective of this project is to create a communication platform that allows users of Android based mobile devices to use services of the virtual campus of UTP. The work team is composed of six professors and researchers in Panama and three in Brazil, with voluntary students in both countries. A complete, step by step use case is documented, including requirement specifications, interface designs based on Android patterns, as well as programming patterns used for the communication between mobile devices and Moodle platform. 相似文献
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The operation of a complicated radiators structure creating a required field in a given area is disturbed often due to different external actions. As an example, the impact of metallic objects approaching off to an antenna system with minimal irradiation on user's body is analyzed. In this case, the zone itself, where the area of a weak field (a dark spot) is created, is generally not approachable for sensors installation. In order to counteract the disturbance of the system operation due to presence of different metallic objects in close proximity to the radiators, two methods based on two information sources are studied. These information sources are antennas driving currents and fields at a predetermined point outside the given area. As an example, the antenna system used in the compensation method for reducing human's body irradiation, to which a metal object approaches, is analyzed. The conditions of severe external actions are considered: a great metal body and a small distance from this body to the dark spot. It is shown that under these conditions of severe external actions the second method based on the field values measuring demonstrates a higher efficiency. A block scheme for structure of an automatic adjustment is suggested. The considered problem is a common one, and developers of radio circuits are faced with them constantly. 相似文献
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Afzaal H. Seyal Hamdani Ibrahim Mohd Noah A. Rahman 《通讯和计算机》2014,(3):255-265
This pioneering study investigates the seventy Bruneian corporate customers' adoption intentions towards using the mobile services. The study uses and validates the VAM (value-based adoption model) for investigating mobile service in different geographical setting contrary to the original study for Mobile Interact. The study combines four external variables such as perceived usefulness, perceived enjoyment, technicality and perceived fee with perceived value in predicting the adoption intentions of using mobile services. The study results indicate that only perceived usefulness is significant predictor of perceived values which are significant indicator of adoption intentions of using mobile services. Based on the results, some recommendations are made for the managerial implications. 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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Laura Margarita Rodriguez Peralta ;Andrea Maria Mendes Abreu ;Lina Maria Pestana Leao de Brito 《通讯和计算机》2014,(2):194-202
Conservation of artworks in museums is a crucial issue to prevent their degradation. Thus, it is fundamental to continuously monitor the environment where artifacts are located. The WISE-MUSE project proposes the use of WSNs (wireless sensor networks) to carry out monitoring and automatically control of museums' environment and structural health. The deployment of a WSN can help to implement these measurements continuously, in a real-time basis, and in a much easier and cheaper way than when using traditional measuring equipment and procedures. Nevertheless, continuous monitoring implies providing immediate information of any abnormal value detected in the museums' environment. Thus, this contribution arises: the development of a new mobile application that allows users to continuously monitor the environment, but specially helps them to be more aware of any undesirable changes that may occur. 相似文献