第四代移动通信关键技术研究

介绍了第四代移动通信技术——LTE-Advanced(包括TD-LTE-Advanced及LTE-Advanced FDD)产生的背景,重点阐述了LTE-Advanced系统中载波聚合技术、增强MIMO(Multi-input Multi-output多输入多输出)天线技术、中继技术、异构网络等关键技术的特点及相应的研究内容。     

LTE-Advanced系统中载波聚合技术的安全研究

主要分析了LTE-Advanced系统中引入载波聚合技术带来的安全需求,并提出了解决方案。载波聚合技术是LTE-Advanced系统的一个关键技术,它的应用给系统安全带来了新的挑战。文章基于3GPP组织关于载波聚合技术制定的相关标准,对载波聚合技术进行了阐述和分析,根据LTE系统的安全实现方案提出了载波聚合场景下的安全解决方案。     

LTE-Advanced增强型技术空口协议最新进展

除了引入载波聚合、中继等新技术外,LTE-Advanced对LTE已有的技术也进行了相应的增强。介绍了LTE-Advanced系统中增强型技术,包括干扰协调增强、针对机器通信的接入机制增强、多媒体广播多播增强,以及在空口协议标准化过程中的最新进展。     

LTE-Advanced关键技术及标准化进展

LTE-Advanced作为4G的候选技术方案,是在LTE基础上的进一步增强。本文介绍了3GPP中LTE-Advanced的各个关键技术及其标准化情况,包括载波聚合、多点协作传输、上下行MIMO传输以及中继等。     

LTE-Advanced系统中的载波聚合技术的研究综述

文章会绍了LTE-Advanced系统中的载波聚合技术,该技术能解决与LTE载波的兼容性,并满足频带资源的需求。文中首先阐述了载波聚合技术酌研究背景及优势,随后对载波聚合的应用场景,切换分析,非对称载波聚合,传输数据流的聚合方式等几方面内容研究状况进行了综述。最后,对进一步需要研究的问题进行了讨论。     

LTE-Advanced中继系统基于资源共享的呼叫接纳控制方法

针对LTE-Advanced中继系统提出了一种基于资源共享的呼叫接纳控制方法。如果目标站点内新用户和切换用户共享资源已经被使用完,切换用户可以使用目标站点为切换用户预留的资源接入系统,而新用户则可以通过目标站点所在小区内的站点间资源共享接入系统。仿真结果表明,与LTE-Advanced系统固定带宽预留方案和LTE-Advanced中继系统固定带宽预留方案相比较,提出的算法能有效降低小区内新用户阻塞率和切换用户的掉话率,并且能够提高系统的资源利用率。     

LTE—A中载波聚合技术研究进展

介绍了LTE-Advanced系统中载波聚合的关键技术,重点分析了载波聚合技术的应用现状及LTE-A中与载波聚合结合的热门技术,并探讨了载波聚合技术进一步发展的工作。     

载波聚合技术对LTE-Advanced空口协议带来的挑战

载波聚合技术是LTE-Advanced标准的一个重要特性,也是实现LTE-Advanced系统百兆带宽运行的最关键技术,但其也对LTE-Advanced空口协议带来了诸多挑战。为了支持载波聚合技术,LTE-Advanced需要对此前的LTE空口协议进行多方面的增强。本文从成员载波分类、上行时钟提前、系统信息处理、无线链路失败处理等方面介绍了目前3GPP正在讨论的针对载波聚合的空口协议增强方案,包括已经形成的结论以及后续还需研究的问题。     

LTE-Advanced载波聚合工程建设策略研究

LTE-Advanced载波聚合工程的建设是当前通信行业最重要的信息化建设之一,并且在2014年中国移动已经率先开展LTE-Advanced载波聚合工程的建设,不仅对其制定了符合实际的总体设计,并对去部署方案进行了详细的规划,主要部署在人员集中的区域,如城市的核心商圈,各大交通枢纽,以及学校医院等地。载波聚合（CA）是LTE-Advanced系统的关键技术,这种技术可以满足该系统对于带宽资源的需求,对于LTE-Advanced载波聚合工程的建设,各大通信公司都是在LTE网络的基础上增加载波聚合功能,本对LTE-Advanced载波聚合工程的建设进行了探讨研究,并对其建设方案进行优化。     

LTE-A载波聚合技术原理及应用场景

载波聚合技术是LTE-Advanced系统中比较关键的技术,文章针对LTE-A载波聚合技术的技术原理及应用场景展开分析,还对载波聚合技术应用于LTE-A中面临的挑战和未来发展展开讨论。     

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