对认知无线电波束成形算法的探讨

对多天线协作双向认知无线电系统中的波束成形算法进行了研究。在多天线协作双向认知无线电系统中,2个主用户系统通过次用户进行信息交换,次用户配置多个天线,且次用户通过叠加信号后将其发送给主用户,所以对分配发送主用户和次用户信息的信号的功率以及设计主用户和次用户的波束成形矩阵等进行了重点研究。依据最大化系统容量的优化准则,得到的优化问题均是非凸问题,因此采用半正定优化和二阶圆锥优化,得到闭合解。仿真结果表明,此方法优于以往的波束成形算法。     

可信电文处理系统的设计

本文介绍了可信电文处理系统的设计思想。为了阻止非法用户窃听、篡改甚至伪造电文,保证在MHS环境下传输用户数据的安全,我们在JSNET基础上,开展了可信电文处理的研究.在MHS设计和使用过程中引进密码学的知识,设计了可信电文处理系统(Trusted Message Handling System—TMHS)。本文还描述了MHS的工作过程,针对数据传输过程中的泄密问题,介绍了可信电文处理系统的设计思想,讨论了在用户代理一级上实施保密措施的具体方法,并对TMHS的性能进行了分析。     

基于混合加密算法的通信网络密文防丢失传输系统设计

传统的通信网络传输系统性能较差,造成用户信息传输准确率较低等问题。为此,设计基于混合加密算法的通信网络密文防丢失传输系统。首先,在硬件平台搭建成功的基础上对加密终端的基带芯片进行选择,并将对称加密算法中的分组密码进行计算,建立RAS密码体制对传输系统进行混合加密,从而实现用户信息数据的防丢失传输。实验结果表明,设计的传输系统信息传输准确率与传统的通信网络传输系统相比具有明显提升,有效避免了用户重要数据信息的丢失。     

基于用户行为的LEO境外业务建模与仿真

LEO(低轨道星座)系统具有组网复杂、承载业务类型多等特点。采用基于用户行为的分层用户模型,对用户在LEO(低轨道星座)系统中的业务行为进行建模,控制用户模型的参数,生成业务流,利用网络仿真工具OPNET将业务流加载在建好的网络模型当中,对LEO系统的境外通信业务量进行分析与仿真,通过仿真得到系统的最大业务承载量,为系统的设计提供可靠依据。     

码位重叠快调频OCDMA系统的多址干扰研究

设计并制作了基于光纤光栅的光编码/解码器,实现单干扰用户、数据速率2.5Gb/s的码位重叠快跳频OCDMA(SO-FFH OCDMA)实验系统.分析SO-FFH OCDMA系统中的多址干扰,并与传统FFH OCDMA系统中的多址干扰进行比较.实验结果表明,多址干扰将恶化SO-FFH OCDMA系统性能,在单个干扰用户的条件下,该系统仍能正确解码数据速率2.5Gb/s的用户数据信息.     

市话程控用户光端机的研制及应用前景

本文从实用化角度,根据今后综合业务数字网(ISDN)发展的需要,着重介绍了市话程控用户光缆中继系统中用户光端机的设计原理、技术特点以及在用户系统中的应用。     

智能汽车出行娱乐系统需求分析及系统设计研究

在人工智能技术不断发展的背景下,人工智能技术得以被应用于汽车制造领域,智能汽车也由此进入了人们的视野。相比于传统的汽车,智能汽车要更具智能化特点,这使其能够给人们带来更加舒适、安全、便捷的驾乘体验。在智能汽车驾驶室内,除了机械控制与方向盘,用户获得驾乘体验有很大部分来自于智能汽车中的车载系统,而车载系统则以出行娱乐系统的使用频次最高。因此,在智能汽车设计中,要想提高用户的驾乘体验,就必须要将车载系统中的出行娱乐系统作为设计重点。鉴于此,文章便对智能汽车出行娱乐系统的研究意义进行阐述,明确车载出行场景需求及其设计方法,并将驾驶室中的用户作为服务核心来分析出行娱乐系统的各种应用场景,以便于对用户的出行娱乐需求进行深度剖析,在此基础上对智能汽车出行娱乐系统的特色功能和系统架构进行设计。     

图书馆用户画像设计与应用研究

用户画像作为大数据环境下的用户分析及服务设计工具,可为高校图书馆开展精准化服务提供了新思路。文章阐述了用户画像的概念及特性,系统梳理了用户画像的国内外研究现状,详细分析了用户画像的构建流程,对用户画像在图书馆领域中的具体应用进行了探索。     

CATV系统用户分配网的设计技巧

本文根据大丰市有线电视实践,浅述了如何对用户分配网进行设计和在设计安装中遇到的一系列问题,进行了分析。 在有线电视的设计和施工中,用户分配系统是整个有线电视系统的最后环节,也是关键的环节。如对用户工作电平的分配不合理,将直接影响用户的收视收听。     

基于EDK的高速数据收发嵌入式用户IP核设计

介绍了基于FPGA嵌入式系统的多通道高速数据收发模块的用户IP核设计。在Xilinx公司的ISE开发工具中,用FPGA器件中的硬核RocketIO及软核FIFO设计用户逻辑;使用嵌入式开发工具EDK封装成可在FPGA嵌入式系统中使用的用户自定义IP核,最后通过实际测试验证了该方法的实效性。     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

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.     

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.