新书推介

《CDMA网络规划与优化》一书从无线通信的基础知识人手，对CDMA的原理及网规网优知识进行了全面介绍，形成了一个较为完整的知识体系。该书内容主要包括：蜂窝移动通信基础、CDMA技术简介、CDMA网络规划、CDMA网络规划专题、CDMA网络优化、CDMA网络优化专题、CDMA网络仿真、CDMA网络规划优化软件等。该书还提供了大量的实例，图文并茂。     

CDMA网络优化浅谈

网络优化的目的是改善网络的通信质量。采用快速有效的网络优化方法，改善网络的性能和服务质量是移动运营商关注的主要问题之一。由于CDMA是干扰受限系统，因此CDMA网络的优化尤为重要。首先介绍了CDMA网络的性能指标，然后详细介绍了CDMA网络优化的分析流程和主要内容。并对CDMA网络优化中的测试方法以及CDMA系统参数进行了探讨。指出网络优化是一项持续性的工作。     

新书介绍

人民邮电出版社新书消息 誗11444《CDMA移动通信网络优化》丛书名:现代移动通信技术丛书作者:万晓榆、万敏、李怡滨定价:20.00元本书从CDMA原理出发,全面介绍了CDMA移动通信的相关技术,提出了CDMA移动通信网络优化工程的总体思路,其中重点讲解了CDMA网络优化中涉及到的各类参数,并在此基础上详细分析了网络优化过程中的常见问题,对部分案例作了深入分析和探讨。本书着眼于CDMA网络优化的实用性———从原理到工程实践,内容由浅入深,可供移动通信运营管理者、CDMA网络优化工程师作技术参考,同时也适合于大专院校移动通信专业本科…     

遗传算法在CDMA网络基站分布规划中的应用

CDMA网络的基站分布规划属于多目标组合优化问题，为此在遗传算法的基础上提出了一种基于成本控制的CDMA网络基站分布规划算法。该算法综合考虑了在CDAM网络规划实际工程中的多种规划目标和要求，能够找到符合CDMA网络建设需要的基站分布方案。     

CDMA无线接入网络部署演进研究

随着中国电信CDMA网络的运营,CDMA网络也随之进入大规模扩容和优化升级阶段,满足未来3G数据业务和适应网络IP化技术趋势成为未来网络扩容和优化的重点,而CDMA无线接入网的扩容和优化成为一个重点。本文通过对CDMA无线接入网,IP网络现状及相关技术的深入分析,结合移动技术演进,深入讨论了中国电信CDMA无线接入网IP化演进方案。     

CDMA移动通信系统中的网络优化技术

文章详细讨论了CDMA移动通信系统的网络优化技术;对目前CDMA网络优化工作中存在的问题进行了深入的分析,并提出了可行的解决办法;最后对网络优化技术的发展趋势进行了探索。     

面向商业运营的WCDMA网络优化

介绍了CDMA网络优化的经验和WCDMA优化中需要考虑一些主要的关键性能指标,描述了CDMA三步优化的步骤。     

浅析CDMA网络规划与优化

文章通过对CDMA网络规划与优化关系的分析,结合实际探讨了联通CDMA发展各阶段网络规划与优化的特点,提出了在现阶段需要进一步实现网络规划与优化协调统一的重要性及实施建议。     

浅谈CDMA网络优化

网络优化的目的是改善网络的通信质量。采用快速有效的网络优化方法，改善网络的性能和服务质量是移动运营商关注的主要问题之一。由于CDMA是干扰受限系统，因此CDMA网络的优化尤为重要。本文简要概述了CDMA无线网络优化的方法及相关措施，对网络优化的准备工作、数据分析以及优化办法进行了相关探讨。     

CDMA移动网络室内自动测试系统的设计与实现

CDMA网络优化已成为移动网络优化的新方向，而室内测试是网络优化数据采集的重要手段。嵌入式技术的发展使得网络优化的室内测试能够实现自动化和智能化，采集和存储全面完整的测试数据，为网络优化提供重要的依据。微缩式的PC模块——PC104微处理器以其高集成性和小体型能完成复杂的测试管理和数据采集任务，从而实现测试系统的自动化。本文介绍了一种基于PC104和数据库技术的CDMA网络室内自动测试系统的总体设计及各功能模块的实现。     

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.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

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.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

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.     

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.     

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.