LTE物理层仿真系统设计与实现

通过对LTE物理层关键技术分析,分别给出不同关键技术点的实现方法,从而设计了一种LTE物理层仿真系统平台,利用该平台对关键技术性能指标进行了仿真与分析.该仿真平台的设计方法和仿真分析结果对评估LTE标准有一定的指导意义和应用价值.     

LTE—A系统上行MIMO信道估计方法研究

以LTE—A系统物理层的PUSCH链路为研究背景,介绍了LTE上行参考信号的设计以及传统的信道估计算法,着重指出了LTE—A上行MIMO信道估计遇到的问题,并阐述了该问题的具体解决方法和公式推导,最后通过对LTE—A上行多天线链路的仿真,验证了该MIMo信道估计方法的可行性．     

LTE上行共享信道的关键技术浅析

本文介绍了LTE上行物理信道和调制,分析了SCFDMA技术。并重点介绍且分析了LTE物理层上行共享信道的设计和工作流程。     

LTE协议解决方案及系统实现

介绍了LTE特点及现状.协议测试及重要性根现状给出了LTE协议测试解决方案并通过安立公司的MD8430A基站仿真器和MD8435A终端仿真器外加两台控制PC搭建测试平台,在平台上成功实现了LTE终端从搜索注册网络建立连接信令流程及数据传输物理层仿真.仿真速率上行达到50Mbit/s下行100Mbit/s的高速率传输,给出了各流程源程序,对于LTE移动终端的研发具有重要的作用.     

3GPP LTE上行链路的仿真研究

在LTE系统中上行链路采用SC-FDMA方案,下行链路采用OFDMA方案。文中对LTE上行链路的物理层进行仿真研究,并深入探讨了频域均衡（FDE）技术在高速率无线通信系统中的作用。从仿真结果可以看出频域均衡技术在多径环境中显著提高了SC-FDMA链路的抗干扰性能。     

LTE的关键技术及其标准演进

介绍了3G演进技术,分析了LTE技术的重要特征：高频谱效率和宽带化．对LTE物理层传输技术和网络结构中的关键技术进行了研究,对目前两种不同制式的LTE演进路线图进行了阐述,讨论了TD—LTE的发展现状。     

R＆S CMW500宽带无线通信综合测试仪发布1.0.10.1版本

LTE（长期演进）将是未来几年使UMTS保持竞争力的关键技术。罗德与施瓦茨公司是市场上第一个推出LTEFDD和TDD测试解决方案的供应商;公司为客户提供灵活易用的解决方案,用于LTE信号的产生和分析,并帮助客户进行LTE射频测试和物理层验证。     

从HSPA到LTE的演进

移动宽带数据业务的发展,加快了运营商从现有的HSPA到LTE演进的步伐。文章分析了LTE相对于HSPA的性能提升,阐述了LTE在网络结构和物理层关键技术两方面的新变化,并对演进路线进行了探讨。     

第一台拥有LTE信令功能的射频测试仪面世

LTE（长期演进）将是未来几年使UMTS保持竞争力的关键技术。罗德与施瓦茨公司是市场上第一个推出LTEFDD和TDD测试解决方案的供应商;公司为客户提供灵活易用的解决方案,用于LTE信号的产生和分析,并帮助客户进行LTE射频测试和物理层验证。     

LTE关键技术与标准演进分析

介绍了3G演进技术,分析了LTE技术的重要特征即高频谱效率和宽带化,对LTE物理层传输技术和网络结构中的关键技术进行了研究,对目前两种不同制式的LTE演进路线图进行了阐述,讨论了TD-LTE的发展现状。     

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.     

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.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.