关于CDMA蜂窝系统中功率控制的分析

本文就ＣＤＭＡ蜂窝系统中的功率控制问题进行了讨论,其中包括功率控制误差的考虑以及功率控制源的选择,在以往的分析中,常常只考虑基于距离的功率,选择,本文引入了对实际环境下基于导频功率的选择考虑,给出了两种方法的比较,数值计算结果显示后者在系统容量上有一定的改善。     

三相电压型PWM变流器的线性化状态反馈解耦控制

三相电压型PWM变流器在实现能量变换的同时可以消除谐波、实现单位功率因数运行,是一个多输入多输出的非线性系统。文章建立了基于开关函数的变流器数学模型,采用非线性变换以及引入变流器交直流侧的动态功率平衡两种方案相结合,得到了线性化的变流器数学模型。在线性化数学模型的基础上,提出了电压型PWM变流器的线性化状态反馈解耦控制。仿真结果表明该控制策略能较好地实现三相电压型PWM变流器有功功率和无功功率的解耦控制,具有较好的动态特性,而且网侧电流谐波含量很低。     

改善电压稳定性的SVC非线性控制策略

对于电力系统电压稳定性的SVC非线性控制的方法和特点进行分析,通过对微分几何理论进行有效的分析,其中主要对反馈线性化方法、非线性控制、直接反馈线性化方法、结构控制方法和智能控制方法进行分析,在电力系统非线性控制中的应用进行分析,同时运用这些方法对电力形同稳定性控制中存在的问题进行分析,更好的提高电力系统的电压稳定性。     

应用于LTE band1的高效率功率放大器设计

设计了一种应用于LTE band1的带有自适应线性化偏置电路的高效率双链式HBT功率放大器。该电路基于InGaP/GaAs HBT工艺设计,通过控制偏置电路电压来选择高功率和低功率模式,对高功率模式仿真和测试结果进行分析。通过调试,最终高功率模式输出功率为28dBm时,增益为27.5dB,功率附加效率为43%,ACPR为-38dBc。在低功率模式输出功率为16dBm时有21%的功率附加效率。     

无线Ad hoc网络中的随机功率控制

 由于能量的限制,无线Ad hoc网络面临网络生存时间、无线资源利用效率以及时延要求等方面的挑战.无线Ad hoc网络中的功率控制已经成为研究领域中的一个热点,其主要目的是降低网络在分发数据包中的能量消耗,降低网络中的通信干扰.为了节省网络能量消耗,提出了一种随机功率控制的方法,其核心是让节点的发射功率随机分布在一个功率区间.通过对随机功率控制和固定功率控制在成功传输概率和网络节能上的理论分析和数值计算比较发现,合理选择随机功率控制中的最小发射功率,可获得与固定功率控制相当的成功传输概率,并能节省网络能量消耗,延长网络生存周期.     

基于双波长双并联调制的大动态范围微波光子链路

为改善微波光子链路的动态范围,提出了一种基于双波长双并联调制的线性化方法。仿真分析了激光器输出光功率漂移对该线性化链路无杂散动态范围的影响,结果显示基于现有的商用器件即可实现该线性化方法。此外,实验对比了单调制器基本链路和双波长双并联调制线性化链路的性能。实验结果显示,线性化后,链路的压缩动态范围提高了1.5 d B,无杂散动态范围提高了15.6 d B,其中无杂散动态范围可达到122.5 d B·Hz4/5。该线性化方法简单、易实现,为光链路动态范围要求较高的应用领域提供了一种很好的解决方案。     

输出电容器的等效串联电阻对滞环控制功率转换器的影响

对于经验丰富的电路设计人员来说,他们都知道滞环控制功率转换器的稳定性取决于输出电容器的等效串联电阻(ESR).假如ESR太小,那么输出电压纹波将会变得较大,并且会对开关信号产生相移.虽然均化和线性化技术在设计与分析固定频率的PWM功率转换器上已有长足的发展,但对滞环控制功率转换器的解析性分析却乏善可陈.由于工作频率是可变的,因此采用非线性控制理论作分析最适合不过.     

基于SVPWM永磁同步电机反馈线性化控制

为了实现对永磁同步电机很好控制的目的,采用反馈线性化的方法,通过求取输出变量的李导数,得到需要的坐标变换和状态反馈变量,设计了控制器。利用MatLab7.6/Simulink做了基于SVPWM的永磁同步电机的反馈线性化控制仿真实验。在加不同大小负载的情况下,验证算法对不同负载速度跟踪的效果,获得了反馈线性化控制对永磁同步电机跟踪控制效果好的结果,得到了反馈线性化控制具有很好的鲁棒稳定性,是控制非线性系统的一个好方法结论。     

CDMA通信系统中基于模糊控制的自适应功率控制

研究了码分多址(CDMA)通信系统中的功率控制问题。首先,对CDMA通信系统模型进行了分析,同时,对系统的信道模型作了一些合理的修正;其次,基于模糊控制理论建立了一个合理的自适应功率控制模型;最后,在数值仿真实验中与传统的固定步长控制进行了比较,说明了基于模糊的自适应功率控制可以使CDMA通信系统获得较佳的性能。     

PWM DC-DC变换器功率级的采样数据模型

将PWM变换器按其工作状态，分别写出开关导通和截止时的数学模型，根据其周其工作的特点，写出其非线性采样数据模型，将该方法用于变换器功率级的建模。以连续导通电压型DC-DC变换器为例，给出了PWM变换器功率级的一种非线性和线性化的采样数据模型，并推导了考虑到控制作用延迟时由控制到输出的传递函数，满足了控制器设计的需要。     

Technology innovation and process integrations for sub-100nm gate patterning

This paper presents a brief overview of the Applied Centura(R)DPS(R)system,configured with silicon etch DPS Ⅱ chamber, with emphasis on discussing tuning capability for CD uniformity control. It also presents the studies of etch process chemistry and film integration impact for an overall successful gate patterning development. Discussions will focus on resolutions to key issues, such as CD uniformity, line-edge roughness, and multilayer film etching integration.     

White organic light-emitting devices based on fac tris（2- phenylpyridine） iridium sensitized 5,6,11,12-tetraphenylnap -hthacene

We have fabricated the white organic light-emitting devices （WOLEDs） based on 4,4＇ -bis（2,2 -diphenyl vinyl）-1,1＇ - biphenyl （DPVBi） and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene （rubrene）. The device structure is ITO/2T-NATA （20 nm）/NPBX （20 nm）/CBP： x%Ir（ppy）3：0.5% rubrene （8 nm）/NPBX （5 nm）/DPVBi （30 nm）/Alq（30 nm）/LiF（0.5 nm）/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris （2-phenylpyridine） iridium [Ir（ppy）3], acts as a yellow light-emitting layer, and N,N＇ -bis- （1-naphthyl）- N,N＇ -diphenyl -1, 1＇ -biphenyl-4,4＇ -diamine （NPBX） acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir （PPY）3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V.     

Complete approach to automatic identification and subpixel center location for ellipse feature

To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction.     

小角度扩展相关性近似算法分析

本论文提出一种在多天线MIMO信道相关性建模中小角度扩展近似理论算法,并应用于分析MIMO系统性能。分析中分别对三种不同角能量分布情况下的空间相关性研发快速近似计算法,并同时提出双模(Bi-Modal)角能量分布情况下的近似运算。通过分析这些新方法的近似效率,可以得到计算简单、复杂度低、而且符合实际的MIMO相关信道矩阵,对系统级的快速高效计算法的研究和系统级的评估以及误差分析具有重要的意义。     

A Versatile Mixed-Signal Pin Approach for Cost-Effective Test of Automotive ICs

Integrated circuits (ICs) intended for increasingly sophisticated automotive applications bring unique test demands. Advanced ICs for applications such as highly integrated automatic braking system (ABS) and airbag controllers combine high voltage digital channels, significant VI demands and precise timing capability. Along with continued missioncritical reliability concerns, the trend toward higher voltage operation and increased device integration requires specialized test capabilities able to extend across the wide operating ranges found in automotive applications. Among these capabilities, automotive test requirements increasingly dictate a need for a cost-effective versatile mixed-signal pin electronics with very high data rates reaching up to 50MHz with a voltage swing of-2 V to +28 V.     

Optical vibration and deviation measurement of rotating machine parts

It is of interest to get appropriate information about the dynamic behaviour of rotating machinery parts in service. This paper presents an approach of optical vibration and deviation measurement of such parts. Essential of this method is an image derotator combined with a high speed camera or a laser doppler vibrometer （LDV）.     

INTEGRATION OF OPTICAL AND WIRELESS NETWORKS

正For a long time,optical and wireless systems/net-works are developed in separate communities witha few attempts for in-depth convergence.In fact,it prom-ises many advantages to combine the optical and wire-less technologies in the levels of systems and networks.Recently,both academia and industry have made manyefforts to enter a new phase of development to take op-tical and wireless systems as fully integrated networks.To provide high bandwidth and reliable service for bothfixed and mobile users,a well-designed network must     

社长序言（英文）

正Happy New Year!As we step into a new year,we take a look back at the key feature topics covered in China Communications over the past 12 months and set out our expecta-     

云计算专题（英文）

正Cloud computing is a novel computing paradigm that utilizes remote cloud resources to achieve a high-performance computation.Cloud provides infrastructure,platform and software as different on-demand services.China has made remarkable progress in cloudbased products and operating system technology.The government,enterprises and research institutions are all active in the development of cloud computing-related projects.Despite the progress,many important problems     

Call for Papers—Feature Topic,Vol.12,No.3,2015

正Smart Grid Communications The electric power industry is undergoing profound changes as the industry aims to capture the promise of a smart grid for a sustainable energy future.Enabled by the advanced sensing devices such as Phasor Measurement Units(PMUs),increasingly powerful