Simplified power control method for cellular mobile communication

The centralised power control (CPC) method measures the gain of the communication links between every mobile and every base station in the cochannel cells and determines optimal transmitter power to maximise the minimum carrier-to-interference ratio. The authors propose a simplified power control method which has nearly the same performance as the CPC method but which involves much smaller measurement overhead     

Linearity and solvability in multicast networks

It is known that for every solvable multicast network, there exists a large enough finite-field alphabet such that a scalar linear solution exists. We prove: i) every binary solvable multicast network with at most two messages has a binary scalar linear solution; ii) for more than two messages, not every binary solvable multicast network has a binary scalar linear solution; iii) a multicast network that has a solution for a given alphabet might not have a solution for all larger alphabets.     

基于柔性测试技术的空空导弹自动测控平台设计

适用性、灵活性和可扩展性是柔性测试技术中的三大特性,测试平台通过光纤内存反射网络并行控制和管理各子单元,既可以根据当前型号的测试任务灵活配置各子单元,适用于当前型号的测试任务,也可以根据未来型号新的测试任务增加新子单元,适用于未来型号的测试任务,使三大特性发挥的淋漓尽致。     

Equivalence of a Nonoriented Line and a Pair of Oriented Lines in a Network

Equivalence of a nonoriented line and a pair of oriented lines (in the reliability-sene) is examined for four types of networks. Type I has one input node and one output node; type II has one input node and two or more output nodes; type II' has two or more input nodes and one input node; type III has two or more input nodes and two or more output nodes. For types I, II, II', every non-oriented line is equivalent to a pair of oriented lines with equal line-reliability. The result corresponds to the presumption that almost every one has taken for granted. However equivalence of such a replacement is not true for a type III network.     

基于资源因子的电力线通信系统自适应资源分配

本文分析了电力线通信系统在每时隙内的最大总功率、各实时用户固定比特和非实时用户最小比特、各子载波允许最大功率和特定比特数的约束下,多用户多业务在多子载波上的自适应资源分配的多层多目标最优模型,并提出一种基于资源因子和用户优先级的功率和速率自适应相结合的资源分配算法。在典型电力线信道环境下其仿真结果表明,本文算法的性能忧于已有的多用户资源分配算法且能满足多用户多业务电力线通信资源分配的多目标要求。     

Understanding next generation Internet

The term next-generation Internet is increasingly common. Almost every system, application, protocol, and product has a next-generation version. There is a White House NGI Initiative, and nearly every major university networking community and institute in the world has some kind of “next Internet” project. There is no single future NGI manifestation. The Internet has grown far too complicated and diverse in its technologies, players, markets, and uses. Perhaps most important, the Internet itself has become a combination incentive and enabling mechanism for an almost incomprehensible number of autonomous development and entrepreneurial activities that constantly come into existence, and have global reach and effect. It has become its own self-sustaining means of reinvention. Ultimately, whatever emerges will be some kind of constantly evolving, grand recursive concatenation of all the myriad next-generation developments within developments     

基于多尺度灰度直方图的图像增强研究

直方图均衡是图像增强的经典方法,但通常都是简单地对整幅图像做一次均衡,这样势必对细节部分增强得不够。多尺度直方图均衡的方法就是对小波分解的各个子带分别作灰度直方图均衡,再根据均衡后的各个子带重构得到处理后的图像,实验证明该方法对图像增强很有效。本文的小波变换采用基于提升格式的第二代小波变换,实现结构简单,计算量低,适合整数到整数的变换。     

ISP技术应用设计方法的探索与实践

结合实例对几种ISP技术应用设计方法的使用进行了详细的介绍与分析,实践证明所有这些设计方法具有启发性、实用性,并架起了ISP技术与数字电子技术设计之间的桥梁。     

试论通信基站节能技术综合评估

近年来通信行业在得到迅猛发展的同时,也步入了高耗能行业,每年仅通信基站的能耗量就一直居高不下。为有效降低企业运营成本、贯彻落实国家节能政策,通信行业开展节能降耗工作势在必行。文中针对通信基站耗能的现状所采用的各种节能技术,取得的节能效果进行了一一综合评估,以供企业参考决策。     

负反馈放大器闭环特性的再研究

关于负反馈放大器,已有文献解决了与每种组态相关的一种增益及输入、输出电阻的计算,但没有考虑源增益及与一种组态相关的另外三种增益的计算,影响了该理论对实际应用的指导。为此,本文在文献(1)的基础上,以电压并联负反馈放大器为例,利用解析法导出了与每种组态相关的四种增益、源增益及输入、输出电阻的关系式,全面总结了负反馈放大器的闭环参数与开环参数之间的关系,所得公式物理意义明确,讲清了相关文献未明确的问题。     

基于代理的协同计算模型研究与实现

针对大规模多数据源实时协同计算结构模型的可扩展进行研究.分析目前协同计算体系结构的缺点,提出一个三层的协同计算结构模型.然后给出该模型中最重要的覆盖层的构建方法,即以自治域为单位征集或部署代理节点,并在每个自治域选出一个或多个代理作为核心代理,核心代理节点采用点对点的Pastry协议互联构成自治域间的覆盖网.实验结果表明,该模型具有良好的可扩展性.     

具有均匀差分分布的一类置换

本文研究了置换的差分分布，证明了如果一个置换的坐标函数的每个线性组合都有非零线性结构，则该置换具有均匀差分分布的充要条件，是它的坐标函数的每个非零线性组合都是只有一个恒变线性结构的部分ｂｅｎｔ函数，并且它的坐标函数的不同非零线性组合所具有的非零线性结构互不相同。还证明了如果一个偶数维置换的坐标函数的每个线性组合都有非零线性结构，则该置换一定不具有均匀差分分布。本文还研究了Ｋ．Ｎｙｂｅｒｇ构造的能够达到最大非线性度的置换，证明了这些置换都具有均匀差分分布，从而解决了具有均匀差分分布的置换的存在性问题。     

A fast single-chip implementation of 8192 complex point FFT

Large-scale single-frequency networks are now being considered in Europe as very promising network topologies to achieve drastic savings in spectrum usage for digital terrestrial television transmission. Such networks are possible using the COFDM system, with large guard intervals (more than 200 μs) to absorb long echoes. In order to limit the spectral efficiency loss to about 20%, very long size fast Fourier transforms (up to 8 K complex points) have to be performed in real time for the demodulation of every COFDM symbol (every 1 ms). This paper presents the first VLSI single chip dedicated to the computation of direct or inverse fast Fourier transforms of up to 8192 complex points. Due to its pipelined architecture, it can perform an 8 K FFT every 400 μs and a 1 K FFT every 50 μs. All the storage is onchip, so that no external memories are required. A new internal result scaling technique, called convergent block floating point, has been introduced in order to minimize the required storage for a given quantization noise, The chip, 1 cm² large with 1.5 million transistors, has been designed in a 3.3 V-0.5 μm triple-level metal CMOS process and is fully functional. The 8 K complex FFT function could therefore be introduced in the coming years in digital terrestrial TV receivers at low cost     

基于查表法的波控系统的设计与实现

波束控制系统是相控阵雷达的重要组成部分。介绍了一种用查表法完成阵面所有单元布相的方法。重点介绍了这种波控系统的原理、组成和具体实现方法。基本思想是先计算得到各移相器的控制码数据,并将控制码编写成查找表格,存储到存储器中。扫描和跟踪时,根据波束指向数据,查得各移相器的控制码,装订到各移相器中。其特点是系统结构简单、集成度高、设备量少、布相时间短。该方法既简单又实用,已用于某大型有限电扫相控阵雷达。     

基于层次模型和融合决策的多姿态人脸识别技术

该文提出了基于层次模型和融合决策的多姿态人脸识别技术,它首先把各人脸按姿态分成几个大类,并且对各大类按人脸个体分成相应子类,然后对各个大类分别进行基于特征脸的人脸识别,最后对各个姿态的人脸识别中间结果进行融合决策得到真正的人脸识别结果,该算法同时也提供了其姿态识别结果,并且大大减小了耗时,该文算法对ORL,UMIST,Stirling数据和一些自拍数据共1200幅人脸图像进行了识别测试实验,其结果令人鼓舞。     

Radio Wave Attenuation due to Clouds from Traditional Models to ML Models—A State of Art

Wireless Personal Communications - The demand for more radio spectrum bandwidths has risen as a result of recent developments in wireless technology from every field of the wireless industry....     

化学机械抛光中的颗粒技术

多层金属化是集成芯片以摩尔定律的速度更替的重要工艺手段.在多层金属化中,平坦的晶圆表面对每道工序的成功完成都是非常必要的,而化学机械抛光工艺能在每道工序之前将晶圆表面抛光.化学机械抛光主要是通过使用颗粒研浆去除材料来实现晶圆抛光.除了研浆本身的化学性质外,研浆的效果也受研磨颗粒性质的影响.如果我们能够更好的理解研磨颗粒...     

APuML: An Efficient Approach to Detect Mobile Phishing Webpages using Machine Learning

Wireless Personal Communications - The recent trend in wireless technology has been tremadously increased the demand of higher frequency bands from every corners of the mobile technology. As next...     

基于cFramework的Web框架设计

基于cFramework的Web应用框架各层次之间保持相对独立,当其中某一层因需要做出修改时,其他各层不受影响,这种软件独立性使得系统的改进、升级变得极为灵活。在系统开发期间,各层的开发可以并行进行,又由于cFrame-work采用了组件技术,许多模块可以被重用,这样可以大大节约开发时间,缩短系统开发周期、提高效率。     

Parallel computing in the commercial marketplace: research andinnovation at work

This is a good time for parallel computer development and research in both academia and industry. The performance improvements predicted by Moore's Law have proven to be quite accurate over many years. However, the doubling of processor performance every 18 months cannot keep up with the growing demand of many applications. The performance of database applications has been doubling every nine to ten months. At last, parallel computer technology has come to play an important role in the commercial marketplace. Multiprocessing has been an active research area for almost 40 years and commercial parallel computers have been available for more than 35 years. After getting off to a slow start, this area has now taken off. Shared memory multiprocessors have dominated this development. This is an area that has sprung out of tireless research and numerous published breakthrough results. The article analyzes some of the reasons for the sudden acceptance of the relatively old parallel computing field, outlines the key properties of a successful parallel computer of the 1990's, and identifies some important research areas and key technologies for the future