基于ETPU的发动机同步策略研究

发动机同步是喷油系统工作的基础。文中针对发动机正常工作和“跛行回家”两种工况,从信号检测、同步策略设计、同步软件实现3个方面的研究。在信号检测的设计满足信号输入的正确性;同步策略的设计满足状态反映及时性和算法有效正确性;同步软件的设计满足协同部件低耦合原则。在此基础上进行了工程验证,证明了该方法的工程可行性。     

基于多轴同步控制系统的研究与应用

基于虚拟主轴的多轴同步控制技术,阐述了多轴同步控制技术的控制原理,介绍了基于虚拟主轴同步控制的控制方法,并基于此方法设计了多轴同步控制伺服系统,将此控制系统应用于MLCC叠层机设备中,取得了较好的实际控制效果.     

基于FPGA的跳频系统快速同步算法设计与实现

同步技术是跳频系统的核心。本文针对FPGA的跳频系统,设计了一种基于独立信道法,同步字头法和精准时钟相结合的快速同步方法,同时设计了基于双图案的改进型独立信道法,同步算法协议,协议帧格式等。该设计使用VHDL硬件语言实现,采用Altera公司的EP3C16E144C8作为核心芯片,并在此硬件平台上进行了功能验证。实际测试表明,该快速同步算法建立时间短、同步稳定可靠。     

基于89CX51单片机的电视信号检测器

介绍了一种电视信号检测器的设计方法,并给出详细的电路图,在此系统中,采用89C2051单片机检测视频场同步信号,根据有无正常的场同步信号来判定电视信号正常与否。     

同步CDMA系统中的MMSE检测器研究

分析了基于实域估计的最小均方误差(MMSE)检测器及其在同步CDMA系统的应用。首先对同步CDMA系统进行了描述,并在此基础上对这种新的MMSE检测器在同步CDMA系统中的设计和近似实现方法进行了探讨。     

一种快速位同步时钟提取方案及实现

本文比较了两种常用位同步提取电路的优缺点,在此基础上提出了一种基于CPLD/FPGA、用于数字通信系统的新型快速位同步方案。此方案借助Altera的设计工具设计了位同步提取电路,并利用FPGA予以实现,同时给出了该电路的仿真试验波形图。     

基于AD7663和CY7C4285V的数据采集系统设计

针对数据采集的速度和采样精度两项重要指标要求，介绍了一种采用高精度模数转换嚣AD7663和高速同步FIFO缓冲CY7C4285V组成的数据采集系统的设计参考方法，分析了ADC和FIFO的工作原理，并在此基础上给出了高速同步数据采集的硬件电路图，同时给出了采FIFO作为采集器与处理器之间进行连接以实现数据采集和传送的同步与协调的设计参考方法。     

遥测数据融合软件的设计与实现

在空空导弹外场试验中,为了提高遥测接收数据的质量,提出了数据融合的思想,并在VC环境下开发此遥测数据融合软件。在此结合具体的外场环境,给出了三种融合的方法:按同步码、帧计数和同步码+帧计数方法融合。详细介绍了从需求分析出发的软件设计过程,各功能模块以及各种融合方法的具体实现流程。实践结果表明该设计很好地达到了预期效果。     

低信噪比下的比特同步设计

比特同步性能设计未有可直接引用的公式且其公式推导繁难,故而工程设计常停留在工程经验层面。针对此问题,以平方律检波比特同步设计为例,在高斯白噪声信道条件下,分析了其功率谱密度,推导了其输出信噪比表达式,总结了影响比特同步性能改善的因素,并在分析结果基础之上,给出了低信噪比下的比特同步设计方法,这对工程设计有着重要的指导意义。     

同步碎石封层车石料撒布器结构设计的研究

本文对同步碎石封层车典型石料撒布器的功能及结构的设计进行了深入研究,综合国内外同步碎石封层车石料撒布器的研究发展现状,提出了较合理的石料撒布器结构形式,此研究可为同步碎石封层车的更新设计提供参考。     

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.     

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.     

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.     

Towards Mobile Ubiquitous Service Environment

In this article we present a perspective on future vision of mobile communications and services which is referred to as Mobile Ubiquitous Service Environment (MUSE). Based on analysis of wireless communications and services, we exploit a conceptual model for MUSE via a top-down approach. The conceptual model consists of three major elements: Terminal Service Environment (TSE), Network Service Environment (NSE) and User Identity (UID). The concept of Always the Best Experience (ABE) is addressed as the hinge in design and development such that the user-centric services could be provided automatically and intelligently in the future diverse wireless world Based on these, we further discuss the issues on design and implementation of architecture of future wireless communication system. Requirements for architecture brought by the new features of MUSE are listed. Moreover, we also address several tradeoffs that should be taken into consideration in design. Finally, the deployment challenges for MUSE, such as reflectiveness of system, security and privacy, as well as peer-to-peer AAA are predicted.Ji Yang received PhD degree on Circuit and System, Bachelor degree on Telecommunication Engineering from Beijing University of Posts and Telecommunications (BUPT) in 2002 and 1993 respectively. Currently, he is an associate professor of BUPT, chief technical supervisor of Wireless Technology Innovation Institute, and vice manager of MTlab of Sino-Germany Software Institute. He leads the research on service and application in Future Forum in China. He also made much contribution to the China Communication Standardization Association (CCSA), including the vision of future Mobile Ubiquitous Service Environment, architecture of future B3G mobile terminal, etc. His research interests include architecture design for mobile ubiquitous networks, theory of self-organization, etc.Zhang Ping is now the professor of Beijing University of Posts and Telecommunications and director of Wireless Technology Innovation (WTI) Institute, BUPT. He has also served on the senior member of C3G Group, China MOST 863 future mobile communication FuTURE project, vice-chairman of China FuTURE Forum, and member of Vision Committee of World Wireless Research Forum(WWRF), he was vice chair of WWRF in 2005. He is also invited as the consultants for many domestic and oversea communication companies. He is very active on the international research activity on Beyond 3G area. He also participated in several European projects such as E2R and MOCCA. Until now, he has published 6 books, around 400 publications in journals and conferences in the area of telecommunications. His main research interests are theory and applications in wireless communication area. He was awarded by government, city of Beijing and Ministry of Information Industry several times for his great contribution to the industry and research activity in China.Hu Zheng is a PH.D candidate in mobile communications engineering in Wireless Technology Innovation Institute (WTI) at Beijing University of Posts and Telecommunications (BUPT). He received B.S degree from Nanjing University of Posts and Telecommunications in 2002, majoring in computer communications engineering. He currently works on serivce aspects of mobile ubiquitous communication system with focus on design and performance evaluation of interaction protocols and services in self-organized service environment.Wang Xu received the B.Tech. degree in electronic engineering from Beijing Polytechnic University (now named as Beijing University of Technology), Beijing, China, in 2002. Now he is working for his Ph.D. degree in Wireless Technology Innovation (WTI) Institute, Beijing University of Posts and Telecommunications (BUPT). His current interests include wireless communications in personal area, ad hoc networks and peer-to-peer system.Li Yinong received the BS degree major in Telecommunication Engineering in 1993 from Beijing University of Posts and Telecommunications, the MS degree and PhD degree major in Telecommunication and Electronic System in 1995 and 2003 from the Beijing University of Posts and Telecommunications. He is currently a lecture of STE (School of Telecommunication Engineering) of BUPT. His main research interests include service modeling, service composition approach, and intelligent service. In BUPT, he has given several lectures to both graduate and undergraduate students such as Information Theory, Speech Recognition, Pattern Recognition and Artificial Intelligence.     

High Speed Curve Interpolating D/A Converter

This paper presents a design of high speed curve interpolating D/A converter. We improve 8-bit data to 12-bit data, so the data resolution increases 16 times than that of original 8-bit data. The curve interpolator is developed from the linear interpolator. The simulation speed curve interpolator is about 500 MHz. The chip is fabricated by 0.8 m double-metal single poly CMOS technology. The active interpolation size of chip is 1 × 1 mm². The power dissipation is 200 mWatts at 5volt and 500 MHz for simulation result and 80 mWatts at 5 volt and 50 MHz for measurement result. The errors of interpolating result of curve interpolators are about 20 times less than that of original signal.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Modulation instability of dispersion-shifted fiber couplers

The nonlinear coupled-mode equations are rewritten by even and odd modes. We study modulation instability (MI) of dispersion-shifted fiber couplers when either even or odd mode is launched alone by using zero-dispersion waveleng threlatively long (quasi-cw) pulses. The result shows that there are new types of MI in both the normal-dispersion and the anomalous-dispersion regimes. MI is concerned with forth-order dispersion and has no relation with third-order dispersion.Quasi-cw can be changed into pulses array under certain conditions. We can extract super short pulse from this. Furthermore,the bandwidth of gain spectra widens and its strength accretes as the input power increases.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

Experimental study of interband and intraband crosstalk in WDM networks

The impacts of interband and intraband erosstalk are studied and compared experimentally. Results show that interband crosstalk can be removed with narrow-band filters and has no influence on signal. Intraband crosstalk will result in signal eye diagram close and BER increasing. When the polarization states of signal and crosstalk align, intraband crosstalk seriously decreases signal quality. But when they misalign, it has little influence. Coherent and incoherent crosstalk are studied experimentally. Results show that coherent crosstalk is less harmful to system performance than incoherent crosstalk.