Two Dimensional Phase Unwrapping Theory Algorithms and Software
Two Dimensional Phase Unwrapping Theory Algorithms and Software，扫描文档，清晰度一般。GTWO-DIMENSIONALPHASE UNWRAPPINGTHEORY ALGORITHMSAND SOFTWAREDennis C. ghigliaSandia National LaboratoriesAlbuquerque, New MexMark D. PrittLockheed Martin CorporationGaithersburg, Maryland藏A WILEY-INTERSCIENCE PUBLICATIONJOHN WILEY SONS, INCNew York Chichester Weinheim Brisbane Singapore / Toronto2005060radar interferogram generated byDeathon each pass, The terrain elevations can be computed from thebut the phase differences must fig problem In regions of steeprrupted where there are radar shadow and "layover"effects. Surfaceoccurred between the two passes, which were 24 days apar alsopThis image was acquired as part of a program for the Terrain Modeling Project Officended byEngineering Center. The SAR data was provided by Radarsat Intenational THinterferogram was generated and provided by Vexcel Corporation, Boulder, Coloradop00This text is printed on acid-free paper.Copyright o 1998 by John Wiley Sons, Inc. All rights reservedNo part of this publicationreproduced, stored in a retrievalsystem or transmitted in any form or by any means, elechanical photocopying, recording, scanning or otherwise,xcept as permitted under Sections 107 or 1O% of the 1976of the Publisher or authorization through payment of theontates Copyright Act, without cither theppropriate per-copy fee to the Copyright Clearance Center, 222750-4744. Requests to the Publisher for permission show(978)ood Drive, Danvers, MA 01923, (978)750-8400, faxnc.. 605 Third A venue. New York, NY 10158-0012(212)850-6011fax(212)850-6008,E-Mail:PERMREQ@WILEY.COMTwo-dimensional phase unwrapping: theory, algorithms, andsoftware/Dennis C Ghiglia and Mark D Pritt.SBN0-471-24935-1(cloth: alk. paper)1. Synthetic aperture radar. 2. Signal processing--Mathematics3. Interferometry. I Pritt. Mark D. [L. Title621.367-dc2l97-3803410987654321;4TWO-DIMENSIONALPHASE UNWRAPPINGFOREWORDTwo-dimensional phase unwrapping is the type of problem that is typically thedomain of the mathematician. It is both complex and abstract However, phaseunwrapping is also the core technology that enables radar interferometryOver the past decade interferometry has changed the way that we use radardata. Radar data are now used for precise measurement of surface topography inclouded regions. Additionally, spaceborne radar systems have proved effectivefor measuring surface changes from earthquakes and volcanic eruptions. Theseapplications have created a new class of radar data users primarily involved inmapping and remote sensing applicationIn Two-Dimensional Phase Unwrapping: Theory, Algorithms, and Softwarethe authors unlock the mystery of phase unwrapping in interferometric datarocessing. This text provides a clear, concise treatment of phase unwrappingthat cannot be found in any other source. It presents for the first time therelationship between theory and application. Its uniform treatment of thevarious phase unwrapping techniques makes it a valuable resource for anyengineer or scientist involved in processing or exploitation of interferometricexpect that radar interferometry will increase in importance over the comingdecade with the development of airborne and spaceborne sensor systemsdesigned to optimally exploit this tcchnology. Two- Dimensionsping: Theory, Algorithms, and Software is an important contribution to ourinderstanding of radar interferometry that will bencfit both research intoadvanced techniques and the design of these future sensor systemsJOHN C. CURLANDEPresident and CEOVexcel CorporationPREFACETwo-dimensional phase unwrapping arises most naturally in, but is notrestricted to, interferometric applications. Measured or calculated phasevalues from two or more mutually coherent multidimensional signals are relatedn a nonlinear manner to a desired physical quantity of interest. The nonlinearityis in the form of"wraps"or cycle discontinuities where an underlying two-dimensional phase is wrapped into the interval (T, r. The wrapped phasemust somehow be unwrapped in order to provide an estimate of the underlyingphysical quantity. Estimation of surface topography from interferometricsynthetic aperture radar(SAR)or extremely accurate profiling of mechanicaparts by optical interferometers are two such examplesOriginally developed for military reconnaissance, SAR is now experiencingnew life in civil applications. In fact civilian and commercial interests are rapidlbecoming the drivers of technology. Clever utilization of the coherent SArimagery in interferometric configurations makes possible the measurement ofsurface topography to accuracies much better than the spatial resolution( 0.3meters to several meters)of the SaR images themselves. Indeed, as is commonplace with interferometers, measurement sensitivities are on the order of theoperating wavelength, which is typically a few centimeters for SAR. Imaginggeometries, noise, and other operational factors degrade performance some-what from centimeter-scale accuracies, but nevertheless SAR interferometrymakes possible global topographic mapping in a timely fashion, in daylight or atnight, in all weather conditions, and with unprecedented accuracyinterferometry also can detect deformations of the earths crust on the orderof millimeters, a capability that shows promise for the timely detection ofearthquakes or volcanic eruptionsThese exciting possibilities have led to an explosive growth in the field of phaseunwrapping as indicated by the increasing number of journal publicationsNewcomers to SAR interferometry and related disciplines will eventuallyonfront the phase unwrapping problem and, undoubtedly, will encounter arather bewildering variety of ideas and algorithms, including those based onneural networks, simulated annealing, cellular automata, genetic algorithms,and other unusual constructs. Which of these are good? Which are not? We doThroughout this book we use the notation(-丌,丌 to represent the interval-丌
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5G网络技术架构
主要讲述当前网络挑战与发展趋势，以及网络总体设计和5G网络的功能特是哪个，和关键技术 。最后总结和展望未来AT-2◇21MT202056/推进组5G无线技术架构白皮书引言在过去的三十年里,移动通信经历了从语音多址技术之外,大规模天线、超密集组网和全频业务到移动宽带数据业务的飞跃式发展,不仅深谱接入都被认为是5G的关键使能技术。此外,新刻地改变了人们的生活方式,也极大地促进了社型多载波、灵活双工、新型调制编码、终端直通会和经济的飞速发展。移动互联网和物联网作为(2)、全双工(又称同时同频全双工)等也未来移动通信发展的两大上要驱动力,为第五代是潜在的5G无线关键技术。5G系统将会构建在以移动通信(5G)提供了广阔旳应用前景。面向新型多址、大规模天线、超密集组网、全频谱接2020年及未来,数据流量的千倍增长,千亿设备入为核心的技术体系之上,全面满足面向2020年连接和多样化的业务需求都将对5G系统设计提出及未来的5G技术需求。严峻挑战。与4G相比,5G将支持更加多样化的当前,5G愿景与需求已基明确,概念与技场景,融合多种无线接入方式,并充分利用低频术路线逐步清晰,国际标准制定工作即将启动。和髙频等频谱资源。同时,5G还将满足网络灵为此,迫切需要尽快细化5G技术路线,整合各种活部署和高效运营维护的需求,大幅提升频谱效无线关键技术,形成5G无线技术框架并推动达成率、能源效率和成本效率,实现移动通信网络的产业共识,以指导5G国际标准及后续产业发展。可持续发展传统的移动通信升级换代都是以多址接入技术为主线,5G的无线技术创新来源将更加丰富。除了稀疏码分多址(SCMA)、图样分割多址(PDMA)、多用户共享接入(MUSA)等新型AT-292◇MT2020(5G)推进组5G无线技术架构白皮书场景与技术需求与以往移动通信系统相比,5G需要满足更加低功耗大连接场景主要面向环境监测、智多样化的场景和极致的性能挑战。归纳未来移动能农业等以传感和数据采集为目标的应用互联网和物联网主要场景和业务需求特征,可提场景,具有小数据包、低功耗、低成本炼出连续广域覆盖、热点高容量、低时延高可靠海量连接的特点,要求支持百万/平方公里和低功耗大连接四个5G主要技术场景。连接数密度。·连续广域覆盖玚景是移动通信最基本的覆总之,5G的技术挑战主要包括盖方式,在保证用户移动性和业务连续性0.1-1GbDs的用广体验速率,数十Gbps的的前提下,无论在静止还是高速移动,覆峰值速率,数十Tbυs/km的流量密度,1盖中心还是覆盖边缘,用户都能够随时随百万/平方公里的连接数密度,毫秒级的地获100Mbps以上的体验速率。端到端时延,以及百倍以上能效提升和单热点高容量场景:要面向室内外局部热点位比特成本降低。区域,为用户提供极高的数据传输速率,满足网络极高的流量密度需求。要技术挑战包括 1Gbps用户休验速率、数|Gbps峰值速率和数十Tbps/km的流量密度低时延高可靠场景主要面向车联网、工业控制等物联网及垂直行业的特殊应用需求,为用户提供亳秒级的端到端时延和或接近100%的业务可靠性保证。AT-2◇2M-2020(56推进组5G无线技术架构白皮书5G无线技术路线面对5G场景和技术需求,需要选择合适的5G将通过工作在较低频段的新空口来满足无线技术路线,以指导5G标進化及产业发展。大覆盖、高移动性场景下的用户体验和海量设综合考虑需求、技术发展趋势以及网络平滑演备连接。同时,需要利用高频段丰富的频谱资进等因素,5G空口技术路线可由5G新空口(含源,来满足热点区域极高的用户体验速率和系低频空口与高频空口)和4G演进两部分组成。统容量需求。综合考虑国际频谱规划及频段传LTE/LTE一 Advanced技术作为事实上的播特性,5G应当包含工作在6GHz以下频段的统一4G标准,已在全球范围内大规模部署。为低频新空口以及工作在6GHz以上频段的高频了持续提升4G用户体验并支持网络平滑演进新空口。需要对4G技术进一步增强。在保证后向兼容的5G低频新空口将采用全新的空口设计,前提下,4G演进将以LE/LTE- advanced技引入大规模天线、新型多址、新波形等先进技术梹架为基础,在传统移动通信频段引入增强术,攴持更短的帧结构,更精简的信令流程,技术,进一步提升4G系统的速率、容量、连接更灵活的双工方式,有效满足广覆盖、大连接数、时延等空口性能指标,在一定程度上满足及髙速等多数场景下的体验速率、时延、连接5G技术需求。数以及能效等指标要求。在系统设计时应当构受现有4G技术框架的约東,大规模天线建统一的技术方案,通过灵活配置技术模块及超密集组阏等增強技术的潜力难以完仝发挥,参数来淸足不同场景差异化的技术需求。全频谱接入、部分新型多址等先进技术难以在5G高频新空口需要考虑高频信道和射频器现有技术框架下采用,4G演进路线无法满足5G件的影响,并针对波形、调制编码、天线技术极致的性能需求。因此,5G需要突破后向兼容等进行相应的优化。同时,高频频段跨度大的限制,设计全新的空口,充分挖掘各种先进候选频段多,从标准、成本及运维角度考虑,技术的潜力,以全面满足5G性能和效率指标要应当尽可能采用统一的空口技术方案,通过参求,新空口将是5G主要的演进方向,4G演进将数调整来适配不同信道及器件的特性。是有效补充。髙频段覆盖能力弱,难以实现全网覆盖,需要与低频段联合组网。由低频段形成有效的3AT-22MT2020(5G)推进组5G无线技术架构白皮书网络覆盖,对用户进行控制、管理,并保证基本的数据传输能力;高频段作为低频段的有效补充,在信道条件较好情况下,为热点区域用户提供高速数据传输。5G无线技术路线主要场景连续广域覆盖6-100GHZ5G高频新空口冷热点高容量5G低频新空口低时延高可靠
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