GNSS系统中通信服务能力比较与电文播发策略研究

随着世界各大导航卫星系统(GNSS)导航定位授时服务性能的日渐完善,在卫星导航系统中发展通信能力逐渐成为趋势,除了北斗系统明确宣布提供导航定位授时和通信数传两大类服务,其他GNSS系统中也出现了部分通信导航融合的服务功能。系统地梳理了欧洲伽利略(Galileo)、日本准天顶卫星系统(QZSS)、印度卫星导航系统(NavIC)和中国北斗卫星导航系统(BDS)目前已经具备或正在发展中的单向通信服务能力,提出了从通信容量、定位实时性、链路鲁棒性和服务弹性4个维度评估通导融合电文性能,综合比较了目前GNSS信号中的通导融合电文性能。针对北斗B2b电文基本框架,提出了一种首次定位时间(TTFF)约束下的竞争式通导融合电文播发策略,兼顾了通信容量与定位实时性两方面性能的动态平衡,为GNSS中通导融合服务的持续优化设计提供参考。     

基于理想解排序的BDSBAS监测站选址综合评价法

北斗星基增强系统(BDSBAS)作为北斗卫星导航系统的重要组成部分，不仅是解决关键行业高完好性需求的重要手段，也是应对国际激烈竞争的重要举措，还是北斗应用走向国际的重要助力。BDSBAS 地面监测站负责卫星信号的采集、分析、预处理工作，作为提供关键数据的基础设施，合理的选址在北斗星基增强系统建设过程中尤为重要，直接影响着 BDSBAS 系统的性能。主要研究分析电磁干扰、GNSS 天线遮蔽角、多路径干扰、收星数、精度因子(DOP)、 观测值精度等因素对监测站站址选择的影响，结合理论基础与真实数据，提出了一种基于理想解排序算法的综合评价办法，来解决在有限方案中监测站最佳位置的选择问题，为后续的站点布设提供参考数据与依据。     

中国第二代卫星导航系统重大专项标准发布

中国卫星导航系统管理办公室北斗卫星导航系统网站发布消息,根据中国卫星导航系统管理办公室“关于发布《北斗卫星导航术语》等17项北斗专项标准的公告”,下列获批的17项北斗专项标准予以公布. BD 110001-2015《北斗卫星导航术语》、BD 410001-2015《北斗/全球卫星导航系统(GNSS)接收机数据自主交换格式》、BD 110002-2015《北斗/全球卫星导航系统(GNSS)接收机差分数据格式(一)》、BD 410003-2015北斗/全球卫星导航系统(GNSS)接收机差分数据格式(二)》、BD 410004-2015《北斗/全球卫星导航系统(GNSS)接收机导航定位数据输出格式》、BD 420001-2015《北斗/全球卫星导航系统(GNSS)接收机射频集成电路通用规范》、BD 420002-2015《北斗/全球卫星导航系统(GNSS)测量型OEM板性能要求及测试方法》、BD 420003-2015北斗/全球卫星导航系统(GNSS)测量型天线性能要求及测试方法》、BD 420004-2015《北斗/全球卫星导航系统(GNSS)导航型天线性能要求及测试方法》、BD 420005-2015《北斗/全球卫星导航系统(GNSS)导航单元性能要求及测试方法》、BD 420006-2015《北斗/全球卫星导航系统(GNSS)定时单元性能要求及测试方法》、BD 420007-2015《北斗用户终端RDSS单元性能要求及测试方法》、BD 420008-2015《北斗/全球卫星系统(GNSS)导航电子地图应用开发中间件接口规范、BD 420009-2015《北斗/全球卫星导航系统(GNSS)测量型接收机通用规范》、BD 420010-2015《北斗/全球导航设备通用规范》和BD 420011-2015《北斗/全球卫星导航系统(GNSS)定位设备通用规范》,以及BD 420012-2015《北斗/全球卫星导航系统(GNSS)信号模拟器性能要求及测试方法》等.     

惯性导航位移参数在大地坐标系中的严密计算方法

对高速移动的物体进行连贯、精准的全球实时定位,需要运用在多方面互补的全球导航卫星系统(GNSS)和惯性导航系统(INS)进行组合导航(GNSS/INS)。针对两种导航系统所属坐标基准不统一的问题,提出了以全球导航卫星系统所依据的大地坐标系为基准,将惯性导航系统测得的三轴位移参数转换为参考椭球上沿大地经度、大地纬度和大地高方向位移值的严密计算方法。从而实现该组合导航系统中两种不同基准导航参数的精确融合,进而有效增强了GNSS/INS组合导航系统的精确性、稳定性和可靠性。     

全球卫星导航系统间的兼容性和互用性

本文介绍了卫星导航系统、星基增强系统及国际 GNSS 委员会(ICG)的概况，重点介绍了 GNSS 系统兼容性和互用性的相关定义和原则，以及 GNSS 提供者和用户团体对兼容性和互用性的相关讨论。最后介绍了亚太区域卫星导航的优势。     

GNSS接收机发展趋势与研究思路分析

GNSS接收机是卫星导航系统的重要组成部分,在新一代的全球卫星导航系统中,有着举足轻重的作用。本文阐述了GNSS系统和接收机的发展现状,指出多系统兼容、室内定位应用、高精度定位、软件无线电技术是GNSS接收机的发展趋势。最后,分析了我国卫星导航系统建设过程中对接收机的研制需求,阐述了GNSS接收机研制开发的一般思路。     

北斗卫星导航系统B1信号伪距偏差问题研究

目前各大卫星导航系统均存在伪距偏差问题,该现象不但不能通过差分的方式进行抵消,在进行双频电离层误差修正时还会被进一步放大,对卫星导航系统服务精度的提高已构成严重危害。然而目前国内对北斗系统伪距偏差产生机理研究甚少,为了最大程度降低伪距偏差对我国北斗卫星导航系统影响,该文首先深入并详细研究了伪距偏差产生机理及特点,在此基础上设计了试验验证方案,利用国内昊平观测站40 m大口径天线,准确测试并评估了所有北斗卫星导航系统(BDS)在轨可视卫星伪距偏差结果。最后根据试验测试结果,提出针对北斗卫星导航系统的接收机主要参数设置建议,从而能够最大程度上减小伪距偏差问题带来的测距误差和定位误差。该文的研究成果可为GNSS信号设计及实现、GNSS监测评估及用户终端参数设置提供有价值的参考依据。     

北斗卫星导航系统在无人驾驶领域的应用

文章介绍了北斗卫星导航系统及当前的热点GNSS技术,阐述了无人驾驶定位的实现方法,比较了地基增强系统与星基增强系统的差异,指出了基于GNSS技术无人驾驶定位的不足及解决办法,对北斗卫星导航系统在无人驾驶领域应用进行了展望。     

卫星导航系统监测站选址因素分析简

监测站是北斗地面运控系统关键部分之一,广泛分布在北斗卫星导航系统的覆盖区域内,实时观测视场内所有导航卫星下行导航信号,其观测数据质量和稳定可靠的运行状态是北斗卫星导航系统业务处理精度的保障.本文从视场因素、电磁干扰因素、多路径干扰因素和环境因素四个方面对影响监测站点位选择需要考虑的因素进行了深入、详细分析,并依据整体组网原则规范了监测站选址要点和流程,采用多种方法对监测站原始观测数据进行分析,深入研究了影响监测站原始观测数据精度的因素,并制定了包括机房结构设计、屋顶天线基座、卫通天线基座、原子钟房、防电涌和防雷系统等诸方面在内的可操作的建设规范,最大限度地保证了监测站原始观测数据质量,保证其为主控站提供高质量、高可靠性的数据,为系统正常的业务运行提供了保障.     

基于RBN台的长波导航系统差分定位

随着电磁环境的日益复杂，全球导航卫星系统(GNSS)固有的脆弱性逐渐显露， 将我国沿海长波导航系统作为北斗系统的备份具有重要意义。本文基于现有 RBN 台站播发差分信息，有效地提高了长波导航系统定位精度，为今后进一步建设我国长波导航差分系统奠定技术基础。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks     

Call for Papers—Feature Topic,Vol.12,No.7,2015

正Information Centric Networking Information-Centric Networking(ICN) is an emerging direction in Future Internet architecture research,gaining significant tractions among academia and industry.Aiming to replace the conventional host-to-host communication model by a data-centric model,ICN treats data content as the first