TD-LTE基站射频一致性的应用研究

LTE技术在移动通信网络中的应用已经成为应用主流,而TD-LTE技术是3GPP无线网络中的重要网元,射频性能对整个网络容量、覆盖范围、服务质量的提升至关重要。通过对TD-LTE基站结构及射频技术的探讨,针对TD-LTE基站射频一致性展开分析与测试,从测试结果来提出TD-LTE网络的应用可行性。     

TD-LTE基站射频设计技术

作为TD-LTE网络覆盖末端的射频基站,RRH对无线网络覆盖和整体网络性能影响巨大。文章针对TDD系统特点,结合当前射频技术发展情况,介绍TD-LTE射频基站系统,并对TD-LTE射频基站的关键技术以及发展方向进行研究与分析。     

TD-LTE基站载波输出功率异常浅析

TD-LTE基站射频性能一致性的测试中最关键一项就是载波输出功率,在测试射频拉远单元(RRU)天线载波输出功率时,会遇见功率偏大或者偏小的问题,与产品设定的额定输出功率有差异,其性能如果不达标,会直接影响到RRU的其他指标性能测试,如果是现网中出现此问题,则直接影响整个网络的覆盖和服务质量。结合实际测试经验,分析导致载波异常原因,避免在工作中出现重复错误。     

TD-LTE基站射频测试浅析

通过对TD-LTE基站发射机和接收机主要射频指标的介绍,研究了主要射频指标的物理意义,并分析了其测试方法及注意事项,最后证实对TD-LTE基站进行射频测试是非常重要且很有必要的。     

TD-LTE基站产品规划研究

TD-LTE基站是TD-LTE无线网络产品中的惟一网元,它具有高带宽、高峰均比、多射频通道、多天线的特点。这些特点对TD-LTE基站产品类型影响很大,并对TD-LTE基站产品设计和规划提出了挑战。本文基于TD-LTE的网络部署需求及基站实现水平,对TD-LTE基站产品规划中的关键问题进行研究,主要包括基站产品类型规划、软件功能规划、硬件规划等。     

TD-LTE基站接收机中镜像抑制滤波器的研究和设计

在TD-LTE基站中,接收机对射频信号中镜像频率的抑制十分重要,在很大程度上是衡量基站接收机性能优越性的重要指标。为了消除TD-LTE基站接收机中的镜像频率,需要在混频器前设计一个抗镜像滤波器。该文提出一种超高频(3GHz~30GHz)LC型镜像抑制滤波器,通过其独特的结构设计来满足TD-LTE基站接收机镜像频率的抑制要求,具有良好的一致性。可以推广到多种通信制式的测试设备、基站等产品中,具有广泛的应用前景。     

5G基站射频传导测试研究与应用

基站是5G网络中的重要节点,其RF(射频)性能与其网络覆盖范围和服务质量高度相关.详细介绍了5G基站的射频测试标准,并通过对测试项目物理意义和实际影响的分析,给出了射频传导测试方法以及测试环境构建中的注意事项,通过对实际基站的测试及对其结果的分析,指出了测试中与精度有关的主要因素.     

TD-LTE系统eNodeB基站故障分析与研究

目前我国各运营商正在如火如荼的进行TD-LTE系统建设,大规模的TD-LTE基站建设,随之而来的是基站故障种类和数量也随之增多,为了更好的打造TD-LTE精品网络,分析、排查、解决基站的故障就显得尤为重要.本文通过工程实践,针对EMB5116 TD-LTE基站设备的常见故障,总结基站的故障处理流程,并以案例形式分析GPS类故障、射频类故障、传输类故障等常见故障的定位与处理方法,从而快速准确的排查处理故障,保证网络平稳可靠运行.     

TD-LTE与TD-SCDMA终端功率控制测试差异性分析

功率控制是终端射频一致性测试的最基本测试用例,功率控制能力的好坏对其他射频测试项的结果有较大影响。本文简单介绍了TD-LTE的功率控制测试用例,并且与TD-SCDMA功率控制测试用例进行了比较分析。     

载频智能节电技术在TD-LTE通信网络中的应用

在移动通信网络的能耗中,基站的能耗超过了整个通信系统能耗的70%,为了能够实现移动运营商的节能目标,对于无线基站节能减耗技术的研究将是一个非常重要的方面。首先从移动通信基站节能的现状出发,分析了TD-LTE系统中基站主设备智能节电系统设计的必要性。在分析无线网络话务时间规律的基础上,针对移动通信网络话务潮汐的特点,根据TD-LTE系统基站主设备的运行原理,分析了载频关断技术在TD-LTE基站系统中实现节能降耗的方法,提出了载频智能关断技术在TD-LTE基站系统中设计原则和技术方案,并且通过测试验证得出了载频智能关断技术在TD-LTE网络中运行的可行性。最后,对此项技术规模性应用所取得的节能效果进行了总结并提出应用建议。     

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