共查询到20条相似文献,搜索用时 140 毫秒
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无线光通信技术与应用分析 总被引:5,自引:0,他引:5
随着高速大容量光通信系统的不断演进,接入网的“瓶颈效应”这一问题越来越突出,无线光通信即是实现光接入网的一种新兴技术。文章详细阐述了无线光通信的基本工作原理和系统组成,并着重讨论了系统实现的关键技术和相关解决方案,接着对无线光通信的优点、缺点、应用和应用动向做了一个简单的介绍。该技术具有广阔的应用前景。 相似文献
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文中主要分析了影响无线光通信性能的各种可能因素,并提出了相应的解决方法以及其实现的可行性,为无线光通信系统的实现进行了较完整的理论分析。 相似文献
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无线光通信是一种重要的现代通信手段,具有频谱资源丰富、抗电磁干扰等优点,可以作为传统无线射频技术的重要补充,有望为未来工业制造提供重要的技术驱动力。文章首先介绍了工业互联网背景下无线光通信的相关应用,并对近年来国内外的研究现状进行综述,针对较为典型的研究进展进行总结,另外阐述了无线光通信系统的信道模型及关键技术,并介绍了射频/可见光异构技术用来保证通信系统上下行链路可靠传输。最后总结了当前无线光通信在工业互联网面临的问题,并对未来发展趋势进行展望,可为未来无线光在该领域的研究和发展提供一定的参考和借鉴。 相似文献
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飞行器中继可以快速构建端到端的通信网络,增强通信系统的覆盖范围和传输能力,强化信号强度和提高数据传输速度,提高通信系统的可靠性。总结了无人机中继技术以及无人机中继在无线光通信中的国内外发展现状,并对无人机中继在无线光通信中关键技术进行了深入研究。对信道特性及其对通信的影响和抑制技术进行了分析,比较了不同调制解调方法的优缺点和通信过程中的光束捕获,跟踪和对准的具体方法,详细介绍了光束的快速对准。最后展望了无人机中继在无线光通信中的发展方向。 相似文献
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电力光通信网为电网安全、稳定、经济运行提供了重要的通信保障。如何在光缆未到位的情况下实现新建变电站通信系统的临时接入,在应急情况下使电力光通信网络能拓展延伸至紧急救援地点,以满足电网安全生产的需求,一直是电力通信部门亟待解决的难题。文章介绍了目前比较成熟的几种宽带无线传输技术,提出了建设以无线技术为基础的移动通信站作为既有光纤通信网的扩展延伸的方案,详细讨论了系统构架及关键技术。 相似文献
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分析突发事件及重要保电状态时电网通信支撑体系的关键作用,结合现阶段主流的电力无线宽带、卫星通信、应急通信指挥车、无线单兵图传系统等技术进行电网应急通信综合平台的研究,引入分析自由空间光通信(FSO)无线接入新技术,提出了电网应急指挥体系下的通信技术保障方案。 相似文献
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针对移动无线光通信中,由于平台抖动、大气湍流等原因造成瞄准偏差,从而影响系统误码率的问题,本文提出一种采用双光束发射双发散角的空间分集技术。在系统的发射端中使用光分路器,将一束光分成两束发散角大小不同的光进行传输。经过计算表明,该方案能有效地降低系统的误码率,改善信噪比和提高稳定性。这种设计方案可以成为移动无线光通信传输系统中切实可行的方案。同时表明,双光束系统两束光发散角的最优选择与偏差角度和传输距离密切有关。 相似文献
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Hebling J. Ka-Lo Yeh Nelson K.A. Hoffmann M.C. 《IEEE journal of selected topics in quantum electronics》2008,14(2):345-353
It is now possible to generate terahertz (THz) pulses with sufficient energy and field amplitude to enable versatile applications in THz nonlinear optics and spectroscopy. In addition, THz waveform shaping at high intensities promises wide ranging new capabilities in THz coherent control. We review recent progress in generation of high-power THz phonon-polariton waves in lithium niobate that can be coupled into free space THz radiation. A ldquopolaritonicsrdquo toolset for control and processing of the THz waves is also reviewed briefly. Recent demonstrations of THz nonlinear optics and spectroscopy are then presented. 相似文献
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地形影响下雷达作用范围三维可视化研究 总被引:7,自引:0,他引:7
雷达的作用范围会受到诸多环境因素的影响,提出了一种地形影响下雷达作用范围三维可视化方法,该方法采样基于混合采样的雷达三维建模完成自由空间中雷达三维表现,同时引入了基于视点的模型简化方法提高绘制效率。基于几何光学法提出了一种雷达探测范围受地形影响的模型修正算法,通过插值计算地形与模型间的相对位置关系,对受地形影响的采样点进行相应修正。实验结果表明,该方法不仅计算速度快,而且能更真实、直观地表现复杂地形环境下雷达电磁信息。 相似文献
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The traditional methods for the characterization of ray trajectories in nonhomogeneous media are based on the Eikonal equation valid in the region of geometrical optics. To apply Eikonal theory to fiber optics requires a fairly extensive use of vector calculus and geometry. Alternatively, through a simple correspondence rule, and a few intuitive guidelines for relating rays to waves, an equivalent set of trajectory equations can be obtained. This approach results in the Eikonal equations for the space evolution of optical fiber rays which are expressed in terms of the mode analysis invariants, azimuthal mode number, and optical waveguide propagation phase constant 相似文献
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Azzam Yasseen A. Mitchell J.N. Klemic J.F. Smith D.A. Mehregany M. 《IEEE journal of selected topics in quantum electronics》1999,5(1):26-32
This paper describes a 1×8 rotary electrostatic micromotor optical switch fabricated using high-aspect-ratio micromachining technology to produce silicon or nickel components which are subsequently assembled to form a switch. The switch consists of a salient-pole micromotor with 1-mm-diameter 200-μm-thick rotor that supports up to a 500-μm-tall, 900-μm-wide mirror. Typical switches were actuated at 50 V, operated for extended periods in room air, and found to have a rapid rotation with an average optical switching time between two neighboring fiber ports of 18 ms. Optical testing was performed at wavelength of 1310 nm in single- and multimode, and at 850 nm in multimode. The optical beam was propagated in free space with minimal divergence through the use of externally mounted collimating gradient-index lenses. With an aluminum coating, the mirror and external optics exhibited an input to output coupling loss as low as 0.96 dB in multimode and 2.32 dB in single-mode. Interchannel crosstalk was less than -45 dB 相似文献
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Deformable mirrors improve optical efficiency of a system by correcting the wave front aberration caused by imperfections in the system components or by turbulent atmosphere in case of telescope optics. Micromachined mirror technology has the potential to substantially reduce the cost of adaptive optics systems. First, a brief review of the work in this field is presented with the goal of informing the reader of the challenges in the micromachined adaptive optics and the implementation tradeoffs including stress-induced curvature of multilayer mirrors. Then, recent results on the silicon micromachined, hybrid integrated microelectromechanical deformable mirrors for adaptive optics developed at the University of Colorado are presented. Various microfabrication processes including surface micromachining, bulk micromachining, and flip-chip assembly are implemented to fabricate high optical fill factor and large-stroke piston-type micromirror arrays. The achieved micromirror deflection for some designs is in the range of 2 to 3.5 μm, which results in the operating wavelength within infrared spectrum. Techniques to integrate microlenses on top of the micromirrors using self-aligned solder or transfer of ultrasmooth mirror plates on top of the micromirror actuators using flip-chip create high optical fill factor devices. Experimental results of aberration correction with such devices are presented 相似文献
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本文主要研究和讨论了采用LED作为光源的照明系统的二次配光器件设计方法以及经过配光后的照度分布。在过去的五十年中,照明光学技术取得了重大的发展和进步,一些新的技术和应用逐渐出现并被应用到照明行业的各个领域,如背光照明领域、户外照明领域,室内照明领域以及投影显示领域等等,而这些技术的核心问题就是如何获得预先设定形状的照度分布。与成像光学不同,照明光学系统属于非成像光学的范畴。因此,在本文中,对照明领域中基本问题的回答将从非成像光学的角度论述,这些观点包括了一些新的设计思想和设计理念,例如"边缘光线理论"、"光学扩展量守恒"、"最大收集率"等等,试图建立一个完整的应用于LED照明二次光学设计的框架。 相似文献
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How fiber optics is being used for proper single-point grounding of distributed electronic systems in industrial facilities with varying existing grounding approaches is outlined. Grounding schemes such as the conventional approach, single-point ground, total single-point ground, and signal reference grid are discussed. A fiber optics solution for a single-point ground system is presented. The author stresses that in all situations, grounding must be recognised first and foremost as a safety method and must adhere to the National Electrical Code 相似文献