基于多用户MIMO系统的用户调度算法研究

随着移动通信系统的快速发展,相关产业技术不断提升,给社会实体产业的扩展注入了新的动能。作为第四代移动通信系统中的核心技术之一,MIMO(即多输入多输出)技术的融入,令整个系统的性能得以增强。文章就基于多用户MIMO系统的用户调度算法进行研究,以期为提高频谱效率以及系统的公平性带来一定的启示。     

4G的核心技术--MIMO OFDM及其同步

第四代移动通信(4G)中系统的速度最高可达100Mbit/s,而带宽在移动通信中是非常稀缺的资源,作为4G中的核心技术的MIMO OFDM能够提高频谱利用率。同步是MIMO OFDM系统的关键问题。     

4G的核心技术——MIMO OFDM及其同步

第四代移动通信(4G)中系统的速度最高可达100Mbit／s，而带宽在移动通信中是非常稀缺的资源，作为4G中的核心技术的MIMO OFDM能够提高频谱利用率。同步是MIMO OFDM系统的关键问题。     

4G中的MIMO-OFDM技术

第四代移动通信提供高的数据传输速率,而MIMO和OFDM提高了频谱效率,从而提供高传输速率和系统容量的技术.两者的结合已经成为第四代移动通信技术研究中的热点.通过这两种技术的优势互补,可以为系统提供高传输速率,同时也能提高系统容量,降低成本.文中详细介绍了这两种技术及信道估计.     

「4G中的MIMO-OFDM技术」

第四代移动通信提供高的数据传输速率，而MIMO和OFDM提高了频谱效率，从而提供高传输速率和系统容量的技术。两者的结合已经成为第四代移动通信技术研究中的热点。通过这两种技术的优势互补，可以为系统提供高传输速率，同时也能提高系统容量，降低成本。本文详细介绍了这两种技术及信道估计。     

4G中的MIMO-OFDM原理及关键技术

本文介绍了4G移动通信中的OFDM技术、MIMO技术的基本原理及MIMO—OFDM系统的关键技术。MIMO技术与OFDM技术结合，成为4G移动通信中有效对抗频率选择性衰落、提高数据传输速率、增大系统容量的关键技术，是第四代移动通信系统研究的热点问题。     

无线MIMO系统的容量分析及其在3G中的应用

在无线MIMO(MultipleInputMultipleOutput)系统信号模型的基础上,分析了无线MIMO系统的容量,讨论了无线MIMO系统提高频谱利用率的基本原理,并且给出收发天线数量和信噪比对系统容量影响的试验结果。最后,对无线MIMO系统的应用,尤其在第三代移动通信中的应用做出了比较详细的说明。     

4G移动通信中的OFDM—MIMO技术研究

介绍了4G移动通信中的OFDM技术、MIMO技术的基本原理及MIMO-OFDM系统的关键技术包括信道估计、同步、分集技术和空时编码技术。MIMO技术与OFDM技术结合，成为4G移动通信中有效对抗频率选择性衰落、提高数据传输速率、增大系统容量的关键技术，是第四代移动通信系统研究的热点问题。     

MIMO-OFDM系统原理及其关键技术

介绍了第四代移动通信系统中的MIMO-OFDM技术,阐述了OFDM、MIMO技术及MIMO-OFDM系统的基本原理与特点,并介绍了MIMO空时信号处理技术、MIMO OFDM同步、信道估计、信道编码以及自适应技术.     

第四代移动通信系统及其关键技术研究

本文介绍了第四代移动通信系统的产生背景、特点和网络架构,讨论了第四代移动通信物理层的关键技术(OFDM、MIMO等)、网络和协议,最后对未来移动通信系统的发展进行了展望.     

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.     

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.     

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.     

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