高铁4G专网多层组网下用户分层驻留方案研究

不同业务、不同用户对高铁4G网络的驻留需求不尽相同,山东移动从基于业务的切换、低速用户迁出特性等手段出发,探索出一套高效实用的高铁专网用户分层解决方案.方案实施后,95％以上的高铁用户可按方案方式驻留,用户感知大幅提升.     

高铁4G专网质量提升探索

高铁专网覆盖是4G信号网覆盖的一个难点;目前高铁专网受限于传统覆盖手段单一,受限于铁路站址建设难度,覆盖质量较公网更差,更不稳定,缺乏行之有效的覆盖手段,本文主要介绍了如何立足现网的基础上提升专网质量,如何通过功能特性研究以及对于不同场景的优化,多维度探索网络性能提升方法,创新的开创有效、实用的专网覆盖手段,解决目前高铁专网覆盖手段瓶颈,突破业界的覆盖难点.     

高速铁路环境下LTE组网技术研究

随着移动互联网时代的到来，高铁旅客对于移动数据业务需求愈加强烈。在LTE试验网部署初期及4G牌照即将发放之际，如何构建一个LTE高铁专网保障高铁旅客的数据需求是一个亟待解决的问题。文章将从高铁列车的特性入手，分析高速移动环境下的网络部署策略，并给出高铁沿线LTE组网建议。     

高业务密度区域MOS质量提升参数研究

随着4G建设的不断完善和VoLTE商用,越来越多的用户将原来由2G承载的语音业务转移到4G,如何确保4G用户的语音通话质量成为网络优化的重点.当前基于用户感知的语音质量评价方法逐渐成为用户语音服务质量评测的最主要标准,MOS值就成为衡量通信系统语音质量的重要指标.本文对MOS算法的原理及优化思路进行研究,提出了系统性提升TD-LTE网络MOS值的参数优化手段,希望对同类网络优化实施起到指导借鉴作用.     

高铁TD-LTE双层网组网规划优化研究

随着4G移动数据业务应用迅速增长,无线网络尤其是热点区域网络负荷已进一步抬升.聚焦五高一地,高铁场景方面在继续做好现有专网基础覆盖的同时,需重点针对高铁专网的网络性能和上网体验持续加强精细优化,对原有单层网覆盖开展容量优化,以此来保障高铁用户的极速4G体验.     

HCS在WCDMA高铁专网优化中的应用

以浙江联通沪杭高铁杭州段为例,分别从WCDMA高铁专网组网分析、小区选择与重选研究等入手,将分层小区结构(HCS)灵活地应用在浙江联通WCDMA高铁专网优化中,通过UE的移动速度区分高铁用户和非高铁用户,以达到将移动速度较慢的非高铁用户推出专网以提升专网用户感知的应用过程,该方法在专网优化实际应用中效果明显.     

VoLTE自动开通关键问题研究

随着自动开通方案的部署,VoLTE用户规模得到了快速提升.通过对VoLTE自动开通部署中几个关键问题研究,提出优化改进建议,提升VoLTE开通部署效果.     

基于参数优化提升VoLTE用户语音感知的技术研究

本文主要探索VoLTE网络优化的过程中,通过后台参数的组合调整来降低VoLTE分组丢失率和提升MOS值的方法。在本文中,以某品牌设备的后台参数为基准,调整站点的pdcchCfiMode、pdcchLaGinrMargin、dlMaxHARQTx/ulMaxHARQTx、tReorderingUl/tReorderingDl等参数,提高信道聚合度,增加MAC层HARQ的重传次数,增大RLC层排序等待定时器,可得到明显的分组丢失率下降和MOS值提升的效果,从而提升VoLTE的语音质量,高效优化VoLTE网络。本研究可大范围推广,提高VoLTE用户的感知。     

LTE语数分层策略研究及优化效果

随着LTE网络的不断发展,D+F多层网覆盖逐渐成熟,根据VoLTE业务的需求特点,将其承载于固定的频率层,实现LTE语音与数据分层。本文从LTE多层网各自优势出发,结合VoLTE业务强覆盖低速率的需求,将VoLTE业务态用户分离至F2频率层,达到优化VoLTE网络覆盖和提升用户感知的目的。     

VoLTE业务调度策略优化及实践

为解决4GVoLTE语音业务过程中出现的用户时延增大、MOS值下降、体验变差的问题。通过对SR配置及调度策略的优化、AMC算法优化、SPS调度策略优化等,采用理论仿真和实际测试相结合的方法,验证算法优化前后对系统性能及用户体验的改善效果。本文提出的优化策略一方面保证了VoLTE业务的优先级,另一方面兼顾了VoLTE业务的空口质量,可有效缩短VoLTE业务时延,降低VoLTE业务的空口丢包率,增加基站VoLTE容量,最终达到提升语音质量和用户体验的目的。     

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.     

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.     

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.     

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.     

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.