基站测试应注意的事项

进行GSM、CDMA、PHS基站的测试是无线电管理工作中的一项重要任务,这就要求我们平时留心各种基站的有关知识,测前精心准备,测时细心操作,测试后用心编写报告。测前准备充分1.要与设台单位协商好测试的时间、数量,并签定协议书。2.要了解基站所使用的频率、工作特性;测试的项目及其指标;测试的依据和相应的无线电管理规定;做到心中有数。以PHS基站为例:PHS无线接入系统使用1900—1915MHz,由于第一信道为895.15MHz,因此我国PHS系统第一可使用的信道号为18。PHS移动接入方式采用TDMA(时分多址)/TDD(多载频时分双工)。中兴公司的5…     

Performance-Aware Corner Model for Design for Manufacturing

We present a methodology to generate performance-aware corner models (PAMs). Accuracy is improved by emphasizing electrical variation data and reconciling the process and electrical variation data. PAM supports corner ($pm sigma$ and $pm hbox{2}sigma$) simulation and Monte Carlo simulation. Furthermore, PAM supports the practice of application-specific corner cards, for example, for gain-sensitive applications.      

平流层通信系统的收发链路性能研究

针对平流层定点信息平台低空试验艇的工作特点,分析了该系统无线数据链路中上下行信道天线收发信号与平台运动方式的关系,分析表明现有天线结构存在传输信号盲区的问题。为此提出了一种基于天线分集的天线收发模型,以改善数据链路性能。该模型实现简单,仿真结果表明该结构可显著提高信噪比并有效消除信号传输盲区,实现信号的可靠传输。     

移动物体的超声波测量

介绍了利用超声波原理研制的“多探头超声波车流检测器”的设计指导思想、设备的功能、结构和优特点。该检测器可用于检测行使中机动车的车高、车长、车辆大小等各种参数。     

砷化镓倍频变容管的研制

倍频变容管的特性直接影响变容管倍频器的性能。文中介绍倍频变容管的设计 ,并制作出了与设计结果基本一致的器件。获得了输入 8GHz、5 0 0 m W,输出 16 GHz,最高倍频效率大于5 0 %的二倍频测试结果 ,并给出了 8mm四倍频器的使用结果     

数据广播用户授权强化方案

l 课题的由来 自数据广播面世以来,解决好用户的加密授权,防止不法商的“盗收盗用”,一直是个难题。解决此难题的方案要么是技术设施条件还不具备,要么是市场成本太高而不实用。 出现严重的“盗收盗用”现象的原因是由于现行数据广播采用空中授权方式的先天不足所致。播出端的空中授权文件中是一系列的合法用户的接收卡号,用户端的接收卡接日软件大致工作流程如图1所示。     

不合格品用于检验分组考核的规定

讨论了不合格品用于检验分组考核的原理。     

航空电子技术用TN—LCD的高级灰度补偿器

介绍一种NW－TN－LCD用高级灰度补偿器,它可给出优良的灰度稳定性,特别是在垂直方向内的低亮度灰度稳定性。     

远程医疗视频通信融合平台解决方案

远程医疗是网络科技与医疗技术结合的产物。通过其行业背景和需求分析，针对医疗卫生系统的不同应用环境和用途，提出了完善的解决方案。     

一种适用于MCU的SDRAM控制器的实现方法

介绍了同步动态存储器SDRAM的特点、操作原理，提出了一种对于MCU等微控制器有着友好接口的SDRAM控制器的实现方法，使得不带SDRAM控制器的微处理器可以方便地实现对于SDRAM的控制。     

Strategies for Peace, Strategies for News Research

Despite the seeming uniformity of media presentation of news about peace, the formats of news reporting and the contest among various discourses allow for the appearance and sometimes prominence of alternative and men oppositional discourses that offer a pragmatic for social action.     

确定圆谐滤波器展开中心的方法

提出相关能量峰值旁瓣比最大法来确定圆谐滤波器的正确展开中心,以用于旋转不变光学图像的识别。这一新方法能保证圆谐滤波器的识别能力是最优的。另外给出了相应的计算机模拟结果。     

Endogenous Stimuli-Activatable Nanomedicine for Immune Theranostics for Cancer

Cancer immunotherapy has witnessed significant advances in the past decade, however challenges associated with immune-related adverse effects and immunosuppressive tumor microenvironment, have hindered their clinical application. Stimuli-activatable nanomedicines hold great potential for improving the efficiency of cancer immunotherapy and minimizing the side effects via tumor-specific accumulation, controllable drug release profile, and combinational therapy by integrating multiple therapeutic regimens. In this review, the recent advances of stimuli-activatable nanomedicines for cancer immunotherapy are first described, with particular focus on endogenous stimuli including pH, glutathione, reactive oxygen species, and excessive enzymes within the tumor microenvironment. Then, the endogenous stimuli-activatable nanomedicines that target tumor cells, immune cells, or periphery immune systems for eliciting sustained systemic immune activation and modulating the immunosuppressive tumor microenvironment, are described. Next, the general mechanisms underlying nanomedicine-based immunotherapy by eliciting anti-tumor immune responses and overcoming immunologic tolerance are described. Further, the emerging application of bioimaging techniques for monitoring immune response and evaluating therapy performance is described. Finally, the authors’ perspectives are provided for the clinical translation of nanomedicine-based cancer immunotherapy.     

Cross residual transform for lossless intra-coding for HEVC

A new lossless intra-coding method based on a cross residual transform is applied to the next generation video coding standard HEVC (High Efficiency Video Coding). HEVC includes a multi-directional spatial prediction method to reduce spatial redundancy by using neighboring pixels as a prediction for the pixels in a block of data to be encoded. In the new lossless intra-coding method, the spatial prediction is performed as pixelwise DPCM but is implemented as block-based manner by using cross residual transform on the HEVC standard. The experimental results show that the new lossless intra-coding method reduces the bit rate of approximately 8.43% in comparison with the lossless-intra coding method in the HEVC standard and the proposed method results in slightly better compression ratio than the JPEG200 lossless coding.     

小区进行多边形划分方法的改进

小区虚拟边界划分是很多优化应用的基础,现有很多软件具备小区边界划分功能,但划分的结果很粗糙,和现实中的实际区域相差较大。通过描述现有划分的机理入手探讨误差较大的原因,并提出了相应的解决方法以及最终的新方法介绍。     

Figure of merit for semiconductors for high-speed switches

Thermal problems set a limit on the speed of semiconductor logic devices. A figure of merit for comparing materials in terms of this limit is presented.