光卫星间通信技术动向

光卫星间通信技术动向一、光卫星间通信简述日本ＡＴＲ光电波通信研究所正在进行人造卫星与地球上的行人通话的通信系统及其技术的研究，这是属于２１世纪的通信技术。这些技术首先是研究把卫星和卫星之间的通信用光来接续，其次是卫星和行人间的移动通信／个人通信技术，...     

卫星间光通信的技术与现状

卫星间光通信的技术与现状卫星间光通信的特点与作用卫星间光通信是卫星间大容扩通信的发展方向。与卫星间的微波通信相比，卫星闪光通信系统具有装置小、重量轻、抗电磁干扰、通信容量大等优点，因而光通信将成为未来卫星间通信的重要手段。卫星间光通信系统有以下几个特...     

美军卫星基础设施建设现状与特点分析

一、美军卫星基础设施建设现状美军的卫星基础设施由空间段和地面段两部分组成。空间段是指主体卫星及星上所有载荷,地面段是指支持用户访问卫星并实现用户间通信的所有地面设施。目前,美军在空间段拥有在轨运行的通信、导航、侦察监视、气象监测等各类军事卫星约100余颗。其中,国防卫星通信系统、军事星、特高频后续卫星、先进极高     

卫星光通信的现状研究

在空间卫星通信中,激光通信技术是一种能够传输大容量数据的计术。文章整理了一些卫星光通信的实验数据。特别是日本宇宙航空研究开发机构(JAXA)的光学轨道间通信工程试验卫星(OICETS)与日本国家信息通信技术研究所(NICT)光学地面站之间的低轨道双向光学通信试验。试验成功的证明了在大气环境影响下激光通信的可行性。     

基于星间激光测距的高轨卫星定位技术研究

针对传统的高轨卫星定位技术存在定位精度低的问题,提出了基于基于星间激光测距的高轨卫星定位技术。在高轨卫星飞行器上安装低噪声激光探测器,借助激光探测器、发射机以及接收器构建星间通信链路,分析接收天线的接收功率与发射天线的发射功率之间的关系,通过激光脉冲传输空间测距与高轨卫星信号捕获接收功率和发射功率获得定位初始数据;再分析星间相对运动和修正电离层误差,得到定位数据的精确解算融合结果。选取精度因子DOP作为评判高轨卫星定位技术的参数,通过仿真实验发现高轨卫星定位技术比传统定位技术的平均DOP值高2.89,由此证明所提定位技术的定位精度更高。     

毫米波星间通信测距一体化技术研究

近年来卫星编队飞行和星间链路技术成为了航天领域的研究热点。在这种趋势之下,需要通过星间的相互通信与相对位置测量来保障编队构型的相对稳定以及实现星间协作。将星间通信和星距测量融合到一体化平台中可以实现通信测距一体化,能够降低负载,符合当前卫星的发展趋势。针对卫星毫米波星间链路设计了一体化波形,同时提出一系列信号处理技术完成波形的同步以及分离,实现了星间通信测距一体化。针对分离波形以及功放非线性对通信信号的影响,使用了基于深度学习的信号检测算法,降低了通信数据的误比特率。仿真结果验证了所设计的一体化波形及信号处理技术在星间链路应用的可行性。     

卫星网络路由技术

由于卫星网络路由技术应用环境的特殊性,研究人员不能根据实际的网络学习环境,只有通过模拟,和仿真工具NS2是指网络仿真设备版本2,NS(网络模拟设备)是开放源码软件仿真平台,与它对网络技术发展研究的科研人员,NS2已包含卫星节点,作为卫星链路模块但这些模块相对比较简单,只有单一层卫星网络.因此,本文提出了多个卫星网络在NS2仿真,实现层间通信网络路由协议多个卫星的研究和开发方法.     

卫星互联网星间激光通信的分析及建议

卫星通信和地面移动通信具有较强的互补性,卫星互联网是当前产业发展的热点,也是未来6G网络的重要组成部分。全球覆盖需要星间组网,但星间通信带宽需求与自由空间信道带来的不稳定性对空间承载网提出了新的挑战。对星间通信及其传输链路进行对比分析,提出了基于星间激光的光传送网络（OTN）承载方案,以充分发挥地面光通信的成熟产业链优势和规模经济优势,构建经济性、兼容性、扩展性强的星地一体化网络。最后展望了星间激光通信的技术演进方向,并提出了我国产业发展建议。     

OASIS：高精度光学瞄准新发展

1.引言近十年来,新的空间光学应用主要涉及激光通信(SILES:卫星间通信)、科学观测(GOMOS:同温层臭氧分布测量)、行星观测(Phobos的MARS实验),为此,对系统的要求涉及两个方面.提高瞄准稳定性和光学装置的精度。对主卫星高精度的主动瞄准,特别在有大量星载仪器的情况下更为重要。     

小卫星未来的军事应用

小卫星的军事用途是人们永恒的讨论话题。有人认为几乎有所有的军事空间活动都可以由小卫星完成。与此相反，美国传统观念认为卫星应该能力强大，冗余的，美国空军科学咨询团已制定了一个未来小卫星连接的智能星座规划。当空军－空间活动的主要业务开始它的“空间和空军”角色转换时，理解空间系统如何融合才能够以最有效和负担得起的方式完成空间任务至关重要。本文研究了小卫星技术的状况，并与军事空间相关的任务相比较。在诸如成     

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.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

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