混合无线定位技术的应用研究

无线定位技术在现代社会中发挥着重要的作用。文中首先描述基于GPS、蜂窝网络和RFID的3种典型无线定位技术的原理,分析了各自的特点,并介绍了混合无线定位技术在手机定位和智能交通管理中的应用实例。研究表明,混合无线定位技术,综合了多种无线定位技术的优点,能有效提高定位准确性和可靠性,是无线定位技术发展的趋势。     

无线定位技术

本文首先介绍了移动通信系统中无线定位技术的广泛应用,讨论了基于移动台和网络的两种无线定位方案,对几类常用的无线定位方法进行了分析,分别阐述了GSM和CDMA两种蜂窝系统中无线定位的应用特点,最后提出了无线定位技术中有待进一步研究的问题.     

蜂窝无线定位技术的发展及应用

本文首先介绍了移动通信系统中无线定位技术的应用,讨论了基于移动台和网络的两种无线定位方案,对几类常用的无线定位方法进行了分析,分析阐述了GSM和CDMA两种蜂窝系统中无线定位的应用特点,最后提出了无线定位技术中有等进一步研究的课题。     

基于混合GPS/蜂窝网的无线定位算法研究及性能分析

介绍了无线定位技术的前景,分析了目前两种主要无线定位技术即基于GPS和基于蜂窝移动通信网络定位的--优缺点,接着提出一种GPS和蜂窝网相结合的混合定位方法.该方法将GPS和蜂窝网TOA测量值相结合,弥补了独立的GPS和基于蜂窝网络定位方法的不足,是一种具有较高定位精度的定位方法.     

基于WIFI的无缝定位技术在网络安全中的应用

介绍了无线局域网技术、网络安全及传统的网络安全问题的解决方案，分析了基于WIFI的无缝定位技术，针对企业的无线局域网使用牦最，提出了一种基于WIFI的无缝定位技术网络安全问题解决方案及技术架构。     

蜂窝系统无线定位原理及应用

本文介绍了无线定位系统的分类、基本的无线；定位技术及基于蜂窝网络的定位方案，讨论了基于时间的定位法及其特点，分析了定位误差产生的原因及其对策，并介绍了基于蜂窝系统的无线定位技术的各种应用。     

无线电定位技术在蜂窝通信系统中的应用及实现

当前，移动用户对基于无线定位技术的新业务的需求不断增加，推动了对无线测距及定位技术的深入研究，向用户提供精确的定位信息已经成为新一代PCS系统的标准业务之一。本文主要介绍几种基于现有蜂窝通信系统的无线定位技术的实现原理，所要解决的主要问题和应用前景。     

一种基于CDMA网络的移动终端定位技术

研究了CDMA2000网络系统中的移动终端手机定位技术,并在此基础上提出一种基于无线传播模型的融合定位技术。该技术在无线传播模型的基础上,借鉴CELL-ID+RTT定位技术的优点,并参考基站配置时的参数设置。该融合定位技术在继承实施方便性和经济性的同时,提高了定位的精度。     

无线蜂窝系统中移动台定位方法

移动台无线定位方法通常分为基于移动台的定位、基于网络的定位及GPS辅助定位3种类型，移动台的定位过程则包括2步：第一步，根据定位类型，估计相应的定位参数；第二步，根据估计出的定位参数，采用相应定位算法确定移动台的位置。该文分析了3种无线定位类型的优缺点，重点介绍了基于移动台和蜂窝网络的无线定位方法，包括定位参数估计技术和文献中提出的几种主要定位方法，并分析了各种定位方法的性能。     

蜂窝移动定位技术的发展与应用

文章介绍了移动通信系统中无线定位技术的应用，对基于网络的无线定位方案中几类常用的无线定位方法以及影响定位精度的主要因素、对策进行了分析和讨论，最后提出了无线定位技术中有待进一步研究的课题。     

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.     

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.     

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.     

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.     

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.     

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 method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.