移动宽带无线接入技术

移动宽带无线接入是当前发展最快的通信领域之一.本文主要介绍了无线城域网IEEE 802.16e、移动宽带无线接入802.20和无线区域网络802.22几大移动宽带无线接入标准的技术特点,并在与第三代蜂窝移动通信系统进行对比的基础上分析了未来移动宽带无线接入的发展趋势.     

宽带无线接入技术演进历程回顾及未来发展趋势

文章回顾了宽带无线接入技术的演进过程,展望了未来的移动应用需求和接入网移动通信体制前景,论述了可能推动宽带无线接入移动通信网未来发展的若干应用,总结了宽带无线接入的技术贡献,分析了我国值得关注的大环境,指出宽带无线接入是发展中的移动互联网和无线城市建设的重要支撑技术。     

未来移动通信中的宽带接入技术

提供移动多媒体综合业务是未来移动通信发展的重要方向,宽带无线接入技术有力促进了这一目标的实现。该文分析了现有的若干接入方案,归纳出宽带无线接入的特点及影响其发展的几项关键技术。结合第三代乃至第四代移动通信系统对宽带业务的要求,指出宽带无线接入对未来通信系统的影响。     

宽带无线技术热点评述

本文通过对无线通信技术发展的介绍,论述了当前宽带无线技术热点问题,主要讨论了宽带无线接入技术、宽带移动通信技术和超宽带通信技术的现状、特点以及发展前景。     

宽带无线技术热点评述

本文通过对无线通信技术发展的介绍,论述了当前宽带无线技术热点问题,主要讨论了宽带无线接入技术、宽带移动通信技术和超宽带通信技术的现状、特点以及发展前景。     

宽带无线接入技术发展趋势

宽带无线接入技术是近年来发展较快的无线通信技术，其中基于IEEE 802。16的宽带无线接入技术尤其受到业界的关注。以802.16技术为重点，首先介绍802.16的技术特点和标准发展现状，然后对宽带无线接入与未来移动通信技术之间的区别和关系作一比较。     

传统宽带无线接入技术

在信息通信领域，发展速度最快、对人们影响最大的两大技术就是宽带网络技术和无线移动通信技术，这两大技术的结合，即为宽带无线接入技术。宽带无线接入技术指从用户终端到业务交换点之间通信链路采用无线链路的宽带接入技术。     

固定宽带无线接入网设计初探

面向公众宽带无线接入中技术相对成熟的固定宽带无线接入,从与固定无线接入、蜂窝移动通信系统的比较分析出发,探讨了FBWA网络设计中在建设背景分析、技术分析和组网以及工程部署几个环节中的方法和特点。     

无线·3G

新一代宽带无线移动通信入选国家重大科技专项在2007年12月26日召开的国务院常务会议上,新一代宽带无线移动通信网入选国家科技重大专项实施方案,主要包括蜂窝移动通信系统的后续演进、宽带无线接入技术的发展和近距离无线互联系统与传感器网络的发展3部分。实施这一     

国家重大专项宽带无线接入总体方案推进会召开

日前,国家重大专项宽带无线接入总体方案推进会在北京召开。会议由国家新一代宽带无线通信网重大专项总体组主办,电子科技大学和普天信息技术研究院有限公司承办。重大专项宽带无线接入总体组各成员单位,宽带无线接入的相关企业代表60余人参加了会议。工业和信息化部电子信息司电子基础处乔跃山处长到会讲话,本次会议就重大专项宽带无线接入总体方案研究工作的分工计划、论证大纲和十二五课题指南建议等进行了讨论并提出意见。国家新一代宽带无线移动通信网重大专项,是我国面向2020年的长期规划,由三部分组成。一是宽带移动通信,主要是蜂窝移动通信系统的后续演进,包括通常所说的HSPA(高速分组接入)技术、LTE(长期演进)技术、4G技术等。二是宽带无线接入,其中面向行业应用的宽带多媒体集群是其主要方向。三是短距离和无线传感器网络。     

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.     

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.     

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.     

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