二进制猫群算法在大规模MIMO天线选择中的应用

在多输入多输出（MIMO）系统中，天线选择技术平衡了系统的性能和硬件开销，但大规模MIMO系统收发端天线选择复杂度问题一直没有得到很好的解决。基于信道容量最大化的准则，采用两个二进制编码字符串分别表示发射端和接收端天线被选择的状态，提出将二进制猫群算法（BCSO）应用于多天线选择中，以MIMO系统信道容量公式作为猫群的适应度函数，将收发端天线选择问题转化为猫群的位置寻优过程。建立了基于BCSO的天线选择模型，给出了算法的实现步骤。仿真结果表明所提算法较之于基于矩阵简化的方法、粒子优化算法具有更好的收敛性和较低的计算复杂度,选择后的系统信道容量接近于最优算法，非常适用于联合收发端天线选择的大规模MIMO 系统中。     

小型移动终端天线设计的改进

在阐述了小型移动终端天线传统设计思想的基础上，考虑到人体影响及比吸收率(SAR)问题等因素，讨论了天线设计改进的途径如采用平衡结构等；并针对现代移动通信系统的要求讨论了自补偿天线、一体化以及软件天线等新的天线设计思想，为小型移动终端天线的近一步研究提供参考。     

地球站天线性能的入网要求及其发展趋势

本文系统总结了地球站天线ＩＮＴＥＬＳＡＴＭ网的最新技术要求，阐述了地球站天线指标的发展趋势，指出了现代卫星通信地球站天线设计研究的方向。     

适用于3GPP信道的可重构天线设计

针对密集用户区高效宽带覆盖核心应用的电磁环境和业务需求，利用开关选择电路和表面贴 装技术，设计了支持选择功能的两单元天线系 统。该天线系统能完全覆盖UMTS(Universal Mobile Telecommunications System)频段。通 过对两天线系统方向图的测试，证明了两单元天线在空间能保持基本互补，且具有较高的稳 定性。     

层叠分布式天线系统混合分集技术

研究了层叠分布式天线系统(CascadeDistributedAntennaSystem,CDAS)空间两层分集的中断概率性能。层叠分布式天线系统包括间隔较远的N个天线簇,每个天线簇包括距离较近的L个天线单元。文中推导了层叠分布式天线系统中断概率的表达式。相比于传统的单天线系统,数值仿真表明采用混合分集的分布式天线系统可以有效抑制快衰落和阴影衰落。     

基于天线选择和功率分配的联合迭代优化算法

当使用所有天线进行无线数据传输时，大规模多输入多输出（Multiple-Input multiple-Output,MIMO）系统中的基站需要使用与天线数相同的射频链路，导致系统的实现复杂度增加，降低了系统的能效。针对能效降低的问题，提出了一种天线选择和功率分配的联合迭代优化算法。该算法在给定初始发送功率的条件下，随机生成一个天线集合作为内循环的初始值，内循环每次从余下的天线集合中选择一根具有最大能效的天线进行替换，得出最优天线集合，求出相应的最优发送功率，并以此作为下次外循环发送功率的初始值。仿真结果表明，所提算法在降低计算复杂度的前提下，几乎可以达到近似于最优穷举搜索算法的能效性能。     

谈天线隔离度

天线之间的耦合是无线电系统间电磁干扰的主要传输途径。天线隔离度是实现其电磁兼容预测所必须的重要参数。文章简要介绍线天线、面天线以及任意形状天线隔离度的分析方法，同时介绍了改善天线隔离度的一些措施。     

移动通信基站天线的关键技术研究进展

基站天线作为移动通信系统中的重要部件，对通信质量起至关重要的作用，其关键技术被广泛研究。通过对基站天线的电调技术、极化技术、宽带技术、阵列天线多频技术和基站天线小型化技术等的研究发展历程介绍，分析了这些关键技术在工程上的实现方法与措施，总结了这5个关键技术今后的研究重点和发展方向。在基站天线下一步的发展中，需要将多个关键技术完美地结合在一起，阵列天线多频技术和基站天线小型化技术将成为今后的研究热点。     

地球同步轨道SAR天线约束分析与数字波束形成设计

针对地球同步轨道合成孔径雷达(GEO SAR）的对地观测需求，同时考虑到发射等其他因素的影响，基于GEO SAR天线的面积以及功率约束分析，在一定的系统参数下，设计了一种将数字波束形成(DBF）技术与反射面技术结合起来的天线。该天线在俯仰向采用DBF可以降低系统对于脉宽的限制，从而降低峰值发射功率；在方位向采用DBF可以减小系统实际工作的脉冲重复频率(PRF)，增大测绘带宽。该设计方法为未来GEO SAR天线的发展提供了理论参考。     

民用飞机CNS系统电磁兼容分析与设计

民机无线电通信、导航、监视（Communication，Navigation，Surveillance,CNS）系统集中了几乎所有的无线电收发设备，设备种类多，工作频段宽且不同设备的工作频率范围重叠，由于天线多，受机体空间约束、空间辐射等因素影响使得电磁兼容（Electromagnetic Compatibility,EMC）问题突出。为此，首先分析了CNS系统的无线电收发设备和天线配置，然后开展电磁兼容性分析找到CNS系统潜在的电磁兼容问题，最后提出从全机天线布局设计、前端电磁兼容加固、频率管理等方面系统解决电磁兼容问题的设计方法。     

Public Financial Expenditure——A Reflection of the Livelihood Improvement

In recent years.China's public finance put social construction high on the agenda and attaches more importance on livelihood insurance and improvement.The 2003-2007 public financial expenditure reflects a fact that the government isputting more emphasis on livelihood andissues concerning the people.     

Voices from the MPC and CPPCC

"Crucial for economic growth.energy utilization has its role in all economic sectors and every aspect of people's daily life.Now we are in dire need of a new profession,namely energy manager.We not only need to have passion and responsibility,but also a scientific approach to conserve energy and cut emissions.APpropriate legislation should be in place.and a special profession should be introduced to ensure the implementation of these laws and regulations."     

Slowdown Trade Surplus Growth

According to Ma Kai＇s economic planning report submitted to the NPC session on March 5th,（Ma Kai is the Minister in charge of the National Development and Reform Commission）,the government has listed the slowdown in trade surplus growth and the steady expansion of external investment as major tasks for 2008.     

Ouyang Riping： A Hero Besides Entrepreneur

A bout fifty years ago. a baby＇s cry broke the sky of quietness, in a small and beautiful town of Hunan province, which surroundcd by green hills and clear water. Though his .birth brought his family great happiness and hope just as any new life, nobody knew that the little boy would get great achievement when he grow up. even start his business oversea, and earn international honor. Let＇s share with you the entrepreneur Ouyang Riping＇s story, which may insights thcsc people who want to succeed and complete oneself in favorite condition or adversity rather leave things to so-called fate.     

Belarus, A Chinese Fort in Europe

＂In recent years, we＇ve found increasing interest from Chinese investors in the Belarus economy. Please let China know, Belarus is always ready to be a true friend to China. We have built a fort in Europe for China,＂ the President of Belarus, Alexander Lukashenko told Zhou Xiaochuan, President of the Bank of China, during his visit to the capital of Minsk, on January 8th, he expressed his high praise and firm confidence in the development of Sino-Belarusian relations.     

What＇s Behind Spring Festival？

Similar to what the Christmas Day means for the westerners,the Spring Festival is the most important celebration for Chinese people.This big event according to Chinese traditional lunar calendar relaxes and pleases the whole country as the happiest gathering time of the year.National-wide crusade for going back home,too-difficult-to-get train tickets,generous family-going-out shopping,Miaohui laundering,New Year Eve reunion dinner,visiting friends and relatives,watching annual TV gala......each piece of clue reminds us of the smell of Chinese Spring Festival.     

KEY WDRDS for Foreign Investment in China

FDI(Foreign Direct Investment),a component of a country's national financlal accounts,is investment of foreign assets into domestic structures,equipment,and organizations.It does not include foreign investment into the stock markets,concession and subcontract.FDI iS thought to be more useful to a country than investments in the equity of its companies because equity investments are potentially "hot money"which can leave at the first sign of trouble,whereas FDI is durable and generally useful whether things go well or badly.     

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.     

Brown＇s Blossom in Britain-China

The overall strategic relationship between U.K. and China is ＂better than ever＂, China- Britain relations have maintained good momentum, with increased high-level exchanges and the reinforcement of strategic mutual trust, with more room for growth in the future.