基于星上多波束天线的卫星功率带宽联合优化新算法

目前已有的卫星功率优化分配策略未考虑功率与带宽的耦合关系 。为了进一步提高星上资源的利用率,在考虑各点波束业务需求差异及共信道干扰的基础上 ,通过构建卫星系统模型,提出一种将卫星功率和带宽联合优化分配的算法。该算法基于系 统公平性建立优化目标函数,并采用迭代方法求解资源优化的最优解。与传统固定分配方式 相比,这种耦合的资源分配方式可根据当前业务需求和信道条件对星上功率和带宽资源进行 实时再分配,提高了系统容量,系统业务匹配率提高10%,具有较高的星上资源利用率。     

火灾报警系统的自动控制原理及实现

自动报警监控系统包括火灾报警信息自动接收、建筑消防信息、气象信息以及城市建筑消防安全应急救助等子系统。具体为公共电话网络信道、信号发送机、数据采集传输及信号控制显示器等设备构成的自动化监测网络。城市火灾自动报警监控系统全程自动化,有效地减少人工监控环节可能造成的火警漏报、迟报,实玫织寸城市人网火灾自动报替系统工作状态实时集中监控与管理。使城市消防形成一个安全防范网。这样大大加强了城市建筑火灾的防范监控能力,实现了城市消防管理的数字化。主要论述了火灾报警系统的自动控制原理及其实现策略。     

一种基于小波变换的监视飞行新方法

如何充分利用有限的信道带宽和实时有效地压缩数据,将更多飞 机飞行参数实时传输给地面试验人员,是提高飞行安全和改进飞机设备的重要手段。基 于小波变换提出了一种监视飞行状态的新方法,借助小波分析在时域和频域同时具有 良好的局部化性质对飞行数据进行有损和无损压缩,并通过飞机现有的VHF信道传输 飞行数据。仿真结果验证了本方法的可行性。     

流媒体传输技术研究

面对有限的带宽和拥挤的拨号网络,要实时实现窄带网络的观频、音频传输,最好的解决方案就是采用流式媒体的传输方式.本文介绍了流媒体的传输方式,分析流媒体传输协议,探讨了媒体流传输的质量控制.     

基于确定性观测的压缩感知MIMO信道参数反馈

在实际资源受限（带宽受限或功率受限）的无线通信系统中,多径信道具有很强的稀疏特性,如何利用这一特点更加高效地将接收端获得的多径信道状态信息（CSI）进行压缩、反馈,是目前信道状态信息反馈技术的研究热点。针对现有多入多出（MIMO）信道状态信息反馈方法中随机观测矩阵需要较大存储空间的问题,引入了确定性Golay测量矩阵,提出了一种基于确定性观测的压缩感知MIMO多径信道参数反馈方法。在接收端对由信道估计得出的信道状态信息利用确定性Golay测量矩阵进行观测,将较少数目的观测值反馈到发送端,在发送端通过重构算法恢复出完全信道状态信息。仿真实验表明,与随机观测相比,采用确定性Golay观测矩阵的方法虽然需要的观测值数目会有所增加,但所需存储空间远小于随机观测矩阵,且利用确定性观测反馈信道状态信息的重构性能与随机观测矩阵相当。     

无线Ad Hoc网络中基于活跃节点数预测的时隙ALOHA算法

针对采用时隙ALOHA算法的无线Ad Hoc网络,考虑数据包到达的动态性与数据包传输的随机性,以最大化吞吐量为目标,同时满足数据队列稳定性,构建了关于接纳控制与竞争接入的随机优化问题。由于在时隙ALOHA算法中数据包传输的最优概率取决于无线Ad Hoc网络中数据队列非空的活跃节点数,提出了一种基于活跃节点数预测的时隙ALOHA算法。该算法要求无线Ad Hoc网络中的所有发送节点实时地侦听通信信道的忙闲状态,计算基于信道状态的活跃节点数条件期望,从而动态地预测无线Ad Hoc网络在不同时刻的活跃节点数,达到网络节点依据局部网络状态信息自适应地优化数据包传输概率的目的。仿真结果表明,所提算法能够有效估计无线Ad Hoc网络在每个时隙的活跃节点数,从而显著提升网络吞吐量并且降低数据包的平均排队时延。     

一种透明传输的双向SPI接口的设计与实现

在高速图像/指令扩频无线传输系统中,前向链路主要为遥控指令或者遥控数据(例如航迹),后向链路主要为高速图像数据,无线传输信道为实时双向链路.针对这种前后向链路数据量不对称而又需要实时传输的特点,设计了一种新型的SPI接口,从而较好地解决了此类数据不对称信道中的数据实时双向透明传输的问题.该设计基于FPGA实现,可与绝大多数具有SPI接口的MCU(MPU)主设备进行双向SPI透明传输,而不需要增加任何协议.给出了SPI接口的仿真波形和实现结果,设计完成后经测试证明,该接口完全满足SPI协议串行数据传输的要求,性能可靠.     

试论基于图像监控的水电厂自动化系统

随着计算机技术及图像监控技术的发展,水电厂自动化系统已由过去的“四遥”（遥测、遥信、遥控和遥调）提高到“六遥”（增加了遥视和遥听）。要使水电厂遥视、遥听与自动化系统融为一体,必须建立一种全新的设计思路,对传输信道及传输方式也提出了更高的要求。本文提出一种基于图像监控的水电厂自动化系统的实现思路（未加说明时,本文的图像监控系统指含遥视和遥听功能的系统）,该系统与一般水电厂自动化系统的不同特点：一是将自动化系统与图像监控系统充分融合在一起,可以实现水电厂信息的全面采集与数字化综合传输,在保证信息传输实时性的前提下,将远动信息和遥视信息通过同一条信道传送到调度中心,采用基于TCP／IP协议的以太网络,可以在已经建成的光纤网络通道上实现远方传输;二是既适应于已有水电厂自动化系统增加遥视和遥听功能,也适用于设计新一代基于图像监控的水电厂自动化系统。     

一种基于短波和散射通信的自组网新方案

结合地空导弹网络化作战对于通信网络的需求,分析了无线自组网在其中的应用 。针对短波通信带宽小、时延大以及信道不稳定的缺点,将对流层散射通信引入到短波自组 网中,设计了多信道的无线自组网。控制信道采用短波,数据业务信道采用散射通信,可以 满足组网的灵活性和实时的业务传输。最后对短波控制网络在OPNET中进行设计和仿真,分 析了不同路由协议的性能。所做工作可为地空导弹网络化作战的通信网络的构建提供参考。     

HFDSR:一种新的短波分层网拓扑的路由算法

本文提出了一种短波分层网络路由算法HFDSR(High Frequency Dynamic SourceRouting),该算法是按需路由算法,由于短波信道具有带宽低、信道质量差的缺点,这势必要求其路由协议消耗尽可能低的网络开销并以链路质量为选径标准.分析和仿真结果表明,这种算法具有数据包发送成功率高,吞吐量大等特点.     

Like An Angel

The central bank of China has raised her deposit rate for 6 times,and deposit reserve rate for 16 times,since last year up to now,which resulted to a great suffer to those small and medium sized enterprises in finance collection.30 percent of China s small and medium sized enterprises have to be closed down, and 60 percent of them are because of finance problem.How to gather the fund is the biggest obstacle for China's enterprises to grow.     

Zhang Hao,Health of wealth

Contribution to the society Zhang Hao owns great opportunity to store intelligence and knowledge, in her early year.Zhang Hao was graduated from Economic Management Department of People's University in 1983 and later finished her study in Advanced Training Program of CEO of Chinese Direct Selling Enterprises in Peking University.     

Investigation on Dumpling Issue——Remarks from China''''s State Council Information Office

From the very beginning of the dumpling incident,China has pav great concernontheoroblem and moved rapidly to find the reason and take further actions.Series of investigations carried in both countries by co-organized experts'team received a primary fruit as the true picture of the incident.Each time,China IS sparing no effort responsibly to solve the products quality dilemma,which other countries face in the same.     

Beijing: Next International Financial Hub?

Beijing‘s new financial dream On May 5,the Beijing Municipal Government released a notice regarding its plans to spur the financial industry, vowing to put forth a strong effort to become the national financial decision- making center,financial management center and financial information and ser- vices center,and formally announcing its ambitious aspiration to become a financial hub with international influence.     

Universal Coverage, Pinpoint Illustration and Profound Impact HTC 2008 Intermedia Recommendation and Introduction Meeting

Holding 88 percent of train media resources across China, based on "Time Cube", on the 2008 Intermedia Recommendation and Introduction Meeting on December 19, 2007, HTC announced its high-profile strategy of tour marketing and tapping the immeasurable potentials on the train. Meanwhile, HTC officially launched its brand new product Olympic Train on the meeting, providing a fabulous platform for all the brands that are prepared to do a smart marketing on the occasion of 2008 Olympic Games.     

Market presence in China strengthened Network growth and Dual-Chinese-Hub Strategy More frequet Flyer Benefit——Air China and shanhai Airlines Join Star Alliance

In the end of 2007, Air China Limited (hereinafter "Air China") and Shanghai Airlines, formally joined Star Alliance at a ceremony held in the new Terminal Three at Beijing Capital International Airport. With the addition of the two Chinese airlines, Star Alliance now has 19 member carriers operating 17,000 daily flights to 897 destinations in 160 countries.     

Investment Guide to Qingdao

Qindao is the host city for several events of the 2008 Olympics, including the sailing competitions which will take place along the shoreline by the city. The unique architecture combination of German and Chinese in the city centre, the German demographic roots and a large Korean expat population, give Qingdao a distinct atmosphere. Too many eye-ball catching strengths turn the beautiful seashore city into an attractive place in foreign investor＇s eyes.     

A New Era for Global Business

Asia Society is the leading global organization working to .strengthen relationship and promote understanding among the people, leaders, and institutions of Asia and the U.S. Every year the Society presents a high-profile Corporate Conference in a selected city in Asia to examine the implications of macroeconomic trends and geopolitical developments for the region and the world. It provides a leading forum for executives to meet the policymakers and business leaders who shape the Asia Pacific business environment.     

China-Pakistan Strengthen Bilateral Custom Cooperation

Mr. Abdullah Yusuf, Secretary General/Chairman, Central Board of Revenue of Pakistart, arrived Shenzhen on April 22 to meet with Mr. Sheng Guangzu, the Chinese Minister for Customs Administration for discussing the bilateral customs issues. During his two-day visit, China＇s Foreign Trade Magazine interviewed to Mr. Abdullah Yusuf in Beijing, he gave the high evaluation on this visit and China＇s great development in the recent years.     

Golden South Africa,Great Development

On the occasion of the 10th panniversary of diplomatic relations between China and South Africa in 2008, China is celebrating ＂South Africa Week＂ to commemorate. H.E. Dr. Nkosazana Dlamini Zuma, the minister of South Africa,