面向能效优化的MIMO系统参数配置

基于点对点多输入多输出（MIMO）通信系统的张量模型，提出了一种以能效最大化为目标的传输参数联合优化方法。首先根据信号矩阵、编码矩阵、信道矩阵构建了接收信号的张量模型和系统能效模型，然后利用张量平行因子（PARAFAC）分解的k-秩条件，通过迭代拟合对能效函数所包含的收发端天线数目、编码长度等传输参数进行联合优化。仿真结果表明，利用穷尽搜索，可以找到一组对应系统能效最大化的传输参数组合。     

一种基于四相编码和优化阵列的MIMO STAP实现方法

多输入多输出（MIMO）雷达多信号间正交性和天线阵列结构影响空时自适应处理(STAP)性能。为了提高多信号间正交性,提出了基于遗传算法优化提高四相编码的自相关峰值并降低互相关峰值方法,保证了多发射信号间良好正交性,基本抑制了盲速影响。针对天线阵列稀疏导致盲速、阵元密布导致天线孔径过小的问题,基于最大连续孔径思想,提出了一种优化阵列结构,在不显著增加天线阵列长度和阵元数目条件下,与四相编码信号结合,实现了动目标检测。仿真实验证明,基于四相编码正交信号和收发阵列设计,MIMO STAP可实现良好动目标检测性能。     

不理想的信道互易性对波束成形技术的影响…

在无线通信系统中,基站可以根据信道互易性使用波束成形（Beam Forming）技术提 升系统性能。信道互易性的准确程度对性能是有影响的,因此需要对其分析以指导系统设计 。对长期演进（LTE）系统的互易性进行建模,指出了终端发送天线和接收天线数目的不对 称性,以及基站信道估计的误差对信道互易性的影响。通过数值仿真验证了不理想的信道互 易性使波束成形性能受到损失,并为系统改进提出思路。其结论容易推广到其他应用波束成 形的无线通信系统。     

基于嵌套张量模型的MIMO中继系统组合接收算法

目前在单向双跳多输入多输出（MIMO）中继系统中，基于嵌套张量模型的接收算法主要采用单步交替最小二乘（ALS）和KRF（Khatri-Rao Factorization）算法。在时变信道且实时性要求较高场景下，计算复杂度高是制约其应用的主要因素。为此，在对单向双跳MIMO中继系统建模基础上，提出了基于嵌套张量模型的双步组合接收算法。该算法通过对接收的数据张量进行重建，将符号估计和信道估计分离，充分利用ALS和KRF的算法优势，有效降低了计算复杂度。同时，对算法的可辨识性进行了分析。仿真结果表明，该算法保持了与传统嵌套PARAFAC的最小二乘（Nested PARAFAC ALS）算法的相同估计性能，在源天线个数变化时，计算复杂度降低了80%以上；在中继天线个数变化时，计算复杂度降低了50%以上。     

不同约束对MMSE软干扰消除Turbo均衡器性能的影响

在MIMO空时编码系统中寻求一种有效的抑制等信道干扰（CCI）的方法是无线通信系统中的关键。基于最小均方差（MMSE）的软干扰消除Turbo均衡器能有效地消除系统共信道干扰与多用户干扰，在频率选择信道下的是一种非常有效的均衡接收技术。它在多天线系统中应用时，需要通过MMSE的方法得到优化的滤波系数；但在不同的约束条件下，会得到不同的滤波系数。本文比较研究了不同的约束方法对系统性能的影响。通过仿真得出了发射天线约束对系统性能起主要作用的结论。     

一种新的MIMO信道模型

实际无线通信环境中发送天线之间以及接收天线之间存在相关性。针对以上特点,从 多径MIMO信道的特性出发,首先建立发射天线相关系数矩阵和接收天线相关系数矩阵,并将 它们引入无线信道的莱斯MIMO信道模型中。最后通过分析LOS MIMO信道相关模型和瑞利衰落 MIMO信道相关模型,给出了具体的建模步骤。仿真结果表明采用本文方法产生的信道模型的 MIMO系统误码率更低,从而验证了该信道模型能够较好地模拟MIMO系统的空间信道。     

八天线TD-LTE系统的波束赋形算法分析

多天线是天线技术的发展趋势,TD-LTE引入了8发2收的天线配置。基于小间距多天 线阵列,利用TDD系统信道互易性,波束赋形技术可以根据上行导频获得信道信息,形成对基 带（中频）信号的最佳组合或者分配,补偿无线传播过程中由空间损耗、多径效应等因素引 入的信号衰落与失真,同时降低同信道用户间的干扰。EBB(Eigen based Beamforming)算 法是波束赋形主要算法之一,该算法中在整个波束空间中,找到使接收信号功率最大的赋形 权矢量。通过仿真,对EBB算法在各种应用场景下的性能进行了分析,结果表明八天线E BB波束赋形算法可以正确实现波束合成,在低速或上行信道信息估计误差较小情况下能够明 显提高系统性能。     

一种MIMO中继系统的自适应自干扰消除方法

为节省频率资源,全双工中继一般采用相同的频率接收和发射信号。由于收发天线之间无法充分隔离,接收天线容易受到自身发射天线的回波干扰。针对宽带全双工多输入多输出（MIMO）中继的自干扰问题,提出了一种基于梯度下降自适应算法的自干扰消除方法。该方法利用中继反馈的已知信号进行自干扰信道估计,并产生一个对自干扰信号的估计信号,从而在接收端将干扰抑制。仿真结果表明,该方法在自适应滤波器的跟踪性能、收敛分布和不同MIMO配置下的均方误差（MSE）性能等方面均取得良好效果。     

基于低峰均比最优导频序列的MIMO-OFDM信道估计

信道估计是多输入多输出-正交频分复用（MIMO-OFDM）系统接收机进行信号相干解调的关键。针对最优导频序列（OPS）在进行信道估计时存在峰均比（PAPR）较高这一问题,设计了一种低PAPR的OPS用于对MIMO-OFDM系统进行信道估计。在建立系统模型基础上,对MIMO-OFDM系统的OPS进行了设计,并利用部分传输序列（PTS）思想设计出低峰均比最优导频序列（EOPS）;将设计的EOPS用于对MIMO-OFDM系统进行信道估计,并对复杂度较高的步骤进行了算法简化,在此基础上分别对各发射天线上信号PAPR的互补累积分布函数（CCDF）和OPS改进前后的均方误差（MSE）、误码率（BER）性能进行了仿真分析。结果表明,分布在多个OFDM符号上的EOPS能够有效降低系统PAPR;同时,与原来的OPS相比,保持了MSE和BER的最优性能。     

用于旋转映射信号的多天线联合Turbo均衡算法

旋转映射信号将编码比特旋转移位后映射为符号，同时采用了隐性交织、加扰等技术，具有交织复杂度低、信道效率高等特点，是一种典型且使用较为广泛的短波通信信号。针对第三方接收条件下，频率选择性衰落造成该类信号难以有效接收的问题，推导了该类信号的软符号解映射、映射方法，提出了一种针对该类信号的多天线联合Turbo均衡算法，实现了软信息在均衡与译码之间的迭代交换。典型短波信道下的仿真结果表明，迭代4次后的两天线联合Turbo均衡在10-5误码率时相对两天线硬判决译码提供了约4 dB的增益，相对两天线软判决译码提供了约1 dB的增益，在10-4误码率时相对单天线Turbo均衡提供了约5.5 dB的增益。     

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.     

A World of Love 2008 Music Grand Ceremony

Under the guidance of the theme slogan of the 29th Olympic Games - One World One Dream, with dream, love and dedication as its theme, the 2008 Music Grand Ceremony ＆ 1000 People Charity Concert on 100 days cotmtdown to Paralympic Gamesis officiaily launched on December 22, 2007. The 2008 Music Grand Ceremony is sponsored by China Disabled Persons＇ Federation, and co-hosted by National Paralympic Committee of China,     

2007 China Harbor Ten People

2007 China Harbor Ten People elected the entrepreneurs who contributed a lot to port economy and enterprises this year trough their talent management.These ten people embody their social responsibility,professional skills,creative ability,and charming personality.Bearing full confidence in China＇s port economy,the port entrepreneurs are brave enough to explore a brand new area,so as to promote harbor economic development. At the very beginning of 2008,China Shipping Website,Dalian Maritime University,and China Port and Shipping In- stitute jointly select the 2007 China Harbor Ten People,demonstrate port entrepreneurs＇ stunning minds,disclose their secrets to success,and providing abundant experiences to others in harbor development.The top ten people are various excellence during the ups and downs harbor development.     

MUYANG GROUP

With its headquarters in the historic city of Yangzhou,Jiangsu Muyang Group Co.,Ltd has since its founding in 1967 grown into a well-known group corporation whose activities cover research ＆ development,project design,manufacturing,installation and services in a multitude of industries including feed machinery and engineering,storage engineering,grain machinery and engineering,environmental protection,conveying equipment and automatic control systems.     

China''''s National Oil Reserve Center was Born

Aseries of events that occurred in October 2007, are rewriting the history of China's energy industry: November 3 an Energy Law Committee asked the public for suggestions on improvements; forty top experts came together to form the National Energy Expert Advisory Committee on November 6; and the National Oil Reserve Center (NORC)became the nerve centre of oil reserves on November 18. Yet, behind the progress of these recent activities remains the fact that international oil prices still hover around a very high price of US$ 90/barrel, and China's oil imports are close to accounting for half of its total oil reserves.     

Sony Style in China

Since the normalization of the diplomatic ties between China and ） Japan, the bilateral economic relations have deepened continually. According to the statistic of Japan, China passed U.S. to become Japan＇s top trade partner as well as is the second largest export market for Japan and is the largest import resource for Japan. Japan companies such as Mitsui, Sumitomo, Sony and Panasonic, have set the subsidiaries in China and explored their scales. This year 2008 marks the 30th anniversary of the signing of the ChinaJapan Treaty of Peace and Friendship.     

China''''s Import and Export of Textiles and Apparel in the Q1

China's textile and apparel industry suffered an unprecedented cold market for exports in the first quarter this year,the result of a few factors including: the appreciating RMB, decreasing export rebate rate,expanding influence of the U.S. subprime crisis, increasing costs of production and rising labor cost.     

Financial Services for Post-Quake Reconstruction

The May 12 earthquake in Sichuan caught Chinese people by surprise and took the nation＇s heart. While mourning the dead and searching for the missing, many services must be provided for the survivors in the wake of the earthquake. Available post-quake financial services have become an important part of the reconstruction effort in the disasterstricken areas of Sichuan province.     

The Frankenstein Syndrome: The Creation of Mega-Media Conglomerates and Ethical Modeling in Journalism

Aristotle saw ethics as a habit that is modeled and developed though practice. Shelly's Victor Frankenstein, though well intentioned in his goals, failed to model ethical behavior for his creation, abandoning it to its own recourse. Today we live in an era of unfettered mergers and acquisitions where once separate and independent media increasingly are concentrated under the control and leadership of the fictitious but legal personhood of a few conglomerated corporations. This paper will explore the impact of mega-media mergers on ethical modeling in journalism. It will diagram the behavioral context underlying the development of ethical habits, discuss leadership theory as it applies to management, and address the question of whether the creation of mega-media conglomerates will result in responsible corporate citizens or monsters who turn on their creators.