江苏联通完成全省GSM1800M网络频率调整工作

近日,工信部正式批准包括江苏南京在内的中国联通16个城市开展LTE—FDD／LTE—TDD混合组网试验。为了确保4G网络用户感知,江苏联通立即启动了全网1800M频率调整实施工作,将GSM网1800M原有的下行频率从1835M-1850M修改为1830M-1840M工作频率。     

TD-LTE与FDD LTE技术对比及融合组网策略分析

为了更好地满足移动用户的海量数据流量业务需求,TD-LTE和FDD LTE融合组网成为全球主流运营商的目标选择。本文从TD-LTE和FDD LTE物理层技术、频谱资源、覆盖性能等方面对比总结了两种制式的差异,并针对TDLTE和FDD LTE融合组网中的关键问题进行了深入分析,最后给出了TD-LTE和FDD LTE融合组网的策略建议,为运营商4G网络的规划和建设提供参考。     

LTE双模组网前景趋向“利好”

基于频段资源的不同,FDD与TDD的融合,未来有一天也会如同GSM 900MHz与1800MHz的融合,将走入"平常"。2012年6月,中国移动演示了全球首次TD-LTE和FDD LTE(内地-香港)两地漫游,并展示了LTE TDD/FDD融合网络的技术方案。半年后的12月18日,香港LTE TDD/FDD融合网络正式启动商用,并成为亚太地区第一个双模LTE网络。     

未来4G是融合组网天下 三大运营商将殊途同归

＂如果TDD和FDD优势互补,统筹共享网络资源,在网络、业务、频率层面实现融合,能节约部署成本,带动4G终端大发展,扩大4G产业规模。＂在中国4G快速发展的背景下,混合组网和融合发展成为业界讨论的热门话题。从当前的形式来看,LTE融合组网是大势所趋,对于中国的三大运营商而言,有利于平衡4G发展的竞争格局。2014年,随着全球4G发展步入快车道,TDD/FDD融合网络数量正在快速增长。据GSMA统计,截至2014年6月10日,已经有300家运营商在107个国家推出商用LTE网络。     

TD-LTE与LTE FDD融合组网策略

随着移动互联网的快速发展以及4G网络规模的急剧扩大,全球范围内的频率资源日益稀缺.借鉴TD-LTE与LTE FDD融合发展的成功经验,对融合组网策略和TD-LTE国际化发展面临的挑战进行了分析,提出了TDD与FDD共平台融合组网的发展模式和策略,并对通信运营商网络的未来发展提出了针对性的建议.TD-LTE与LTE FDD融合组网已成为大趋势,LTE融合组网的方式作为通信运营商的重要战略布局,应该提前在LTE总体规划中予以考虑.     

LTE融合组网的趋势和面临的问题

国际上在TDD和FDD融合方面形成了2种主要的模式：一种模式是在原来2G、3G之上建设一个LTE FDD网络,进行融合组网,而TD-LTE则作为一个独立的、松散的附加网络,采用类似于Wi-Fi的使用方式;另一种模式是将TD-LTE和LTE FDD紧密地捆绑在一起,首先相互切换,并和2G、3G网络都实现融合。这2种组网模式在国际上都有现成的范例。     

5G分场景TDD与FDD参数优化策略研究

2020年随着5G全面商用及大规模工程建设，无线网络正式进入并将长期处于“大建设、大调整、大优化”周期，2/4/5G多制式、5模13频的复杂无线网络成为常态。面对4/5G无线网络协同发展，现网存在多张网共存的格局。为不断提升用户感知，在TD-LTE E\D\F\FDD900\1800分层组网下，探索在不同场景与业务需求下，最佳的TD-LTE和LTE FDD融合组网策略。     

4G就在你眼前——4G牌照发放助力实现“中国梦”

针对如何确保4GLTE／LTE—A有效国际化,以及确保FDD／TD．LTE／LTE—A能有机协同、融合推进,提出了几点发展策略：执行国家创新驱动战略,确保TD．LTE成功发展,重视TDD／FDD-LTE／LTE。A协同融合发展,4G发展应与2G／3G后向兼容及与5G前向协同,推进智慧城市建设、新型城镇化及两化深度融合,打造健康的产业生态环境。     

LTETDD与FDD制式技术对比与融合组网策略

LTE TDD/FDD是4G网络的两种不同制式。目前,越来越多的运营商开始采用两种制式进行融合组网。本文分析了LTE TDD/FDD两种技术体制之间性能的差异,提出了未来LTE TDD/FDD融合组网的实施建议,为运营商4G网络的规划、设计和建设提供参考。     

浅谈移动通信FDD-LTE与TDD-LTE技术融合组网

随着移动端设备的普及,人们逐渐意识到网速的重要性,传统的2G/3G网络再也无法满足人类的日常需求,因此4G网络应运而生,尤其是近几年来4G网络的发展速度已经达到一个前所未有的峰值。随着LTE牌照的过审、发布,中国移动、中国电信、中国联通这三大主流运营商先后发布了针对4G网络建设的计划,而根据我国工信部的具体要求,对LTE的建设需要按照TDD与FDD两种网络技术进行融合组网进行网络覆盖,这三大运营商对4G网络的发展建设也并不相同,中国移动主要针对TDD进行单模式的升级操作完成4G建设,而电信与联通则实现了TDD与FDD的融合组网模式。为了使用户享受到更好的4G移动互联网业务体验,本文从TDD与FDD的技术特点下手,针对TDD与FDD的融合组网模式进行简要分析。     

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.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

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.     

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.     

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.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.