基于AD9361的掌上型LTE RRU设计与开发

当前小体积远端射频单元（Remote Radio Unit,RRU）主要是皮站级别的Pico-RRU，其重量和体积仍然难以满足掌上型的要求。为此，采用高集成度的AD9361芯片来实现长期演进（Long Term Evolution，LTE）宽带收发信机功能，配合时钟同步模块、放大器模块和控制接口电路等一起构建低成本的掌上型RRU。主要解决了基于AD9516的时钟同步、低相位噪声设计和高灵敏度接收机设计三个技术难点，成功实现了掌上型、高性能、低成本的设计目标。整个RRU样机尺寸为18 cm×10 cm×2 cm，质量约500 g，量产成本千元以内。测试表明，该RRU下行误差向量幅度（Error Vector Magnitude，EVM）小于3%，优于3GPP要求的8%；10 MHz带宽时上行接收机灵敏度优于3GPP要求的-93.5 dBm。     

A study on the deployment of high-speed broadband networks in NUTS3 regions within the framework of digital agenda for Europe

This paper investigates the high-speed broadband situation in the EU and its prospects. It uses a deployment model to estimate the investment required to meet the Digital Agenda for Europe (DAE) broadband targets set by the European Commission in its Europe 2020 strategy at different stages: as of 2016, after expected operators’ deployment, after public subsidies and leveraged investment, and as expected in 2020. The model uses data at the NUTS3 level, which is the most granular level that has data available on the status of broadband deployment, to arrive at a coherent and comparable framework. From the different perspectives on the investment to meet DAE targets, the paper concludes on the need for an appropriate combination of incumbent and alternative operators investments, public subsidies and leveraged investments, and new investments, both public and private and non-existing as of 2016, examining their feasibility and the impact of different regulatory, technical, and policy strategies.     

LTE终端的形态演变分析

为促进信息消费,我国在2013年底发放了4G牌照,LTE在我国即将迎来快速发展期。LTE网络自2009年12月北欧首个商用局开通以来,已经历了全球范围的部署热潮。而用户数则是在2011年中期北美市场推出数款支持LTE的手机终端后,才迎来了爆发式增长。分析表明,LTE网络的深度部署,创新资费模式的推出和语音解决方案的成熟,有力的推动了终端形态从数据终端向手机终端的过渡。随着网络的成熟,手机终端在LTE终端中的占比还将持续上升,最终成为LTE终端的绝对主流。     

第三代移动通信主流技术标准及其演进

分析第三代移动通信技术标准分类特点,阐述不同标准移动通信技术发展技术的演进过程.     

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。     

一种改进的LTE系统下行同步算法

LTE（Long Term Evolution）系统中,作为小区搜索的第一步,符号定时算法需要具备很强的鲁棒性。为了进一步增强现有符号同步算法的抗频偏性能,提出了一种优化的符号同步算法。该算法一方面保持已有分段相关同步算法的优点,同时考虑结合预频偏处理来进行符号定时与粗频偏的联合估计,再将多个相关运算集做叠加处理。理论分析和仿真实验结果表明,在多径信道下,所提算法在完成符号定时和粗频偏估计的同时,大大提高了系统抗频偏性能。     

An integrated model for analyzing the development of the 4G telecommunications market in Taiwan

Previous studies of development trends in the telecommunications industry have estimated market potential but have seldom integrated analyses of customer preferences and macro-environmental factors (political, economic, social, and technological analyses). In order to more accurately analyze 4G technological trends and market penetration and provide implications for businesses and policymakers, we use conjoint analysis to analyze customers' preferences for telecommunications technology and integrate the results with data from scenario analysis and the Delphi method to address possible scenarios for the development of 2G, 3G, Worldwide Interoperability for Microwave Access (WiMAX), and long-term evolution (LTE) in Taiwan. We then use the innovation diffusion model to forecast the sales volume for these four technologies in Taiwan over the next 10 years. Finally, we provide suggestions for policymaking and strategic actions for 4G stakeholders.     

试论中国移动的商用LTE新技术

当前经济全球化不断发展使得全世界部署TD—LTE网络逐渐投入到世界运用当中,而中国移动在这方面的工作是最为显著的。其设置过程中不仅考虑了具体的计划安排,还针对不同的,隋况将后部署TD—LTE进行安排。在这种情况下的基站和回程网络元件能够和与TD—LTE之间相互协调作用。此次研究重点针对中国移动商用LTE新技术展开分析。     

LTE系统中利用信道估计的天线端口数检测算法

长期演进(LTE）系统中使用多输入多输出(MIMO)技术来改善通信质量并提升信道容量。天线端口数通过循环冗余校验（CRC）掩码的方式隐含于物理广播信道（PBCH）中，遍历1、2、4三种天线端口数情况，分别作为PBCH解码配置，以CRC校验通过并且PBCH解码成功作为确定天线端口数的标志，从而造成冗余计算和时延的产生。为此，提出了一种基于信道估计的天线端口数检测算法，利用正交频分复用（OFDM）调制的LTE信号在空口环境中受频偏和时延影响，造成信道估计结果相位的线性累加，再通过线性回归方程的门限匹配，解决天线端口数检测中频偏影响大、计算量过多和盲检等问题。理论分析和仿真结果表明，该算法复杂度低、时延小，且在残余频偏较大时具有较高的正确率。     

Polish experience from first-ever spectrum auction

The Polish 4G spectrum auction was a watershed event for the Polish telecommunications market. For the first time in history, the Office of Electronic Communications decided to award spectrum by using an auction process. Polish regulators implemented a simultaneous multiple-round ascending-bid auction, which was widely used worldwide for selling spectrum. The process leading to the auction and the auction itself was lengthy and eventful. Due to the wrong auction design, the auction dragged on indefinitely, causing a delay in spectrum distribution. The auction ended only as a result of the government's intervention, after 8 months (513 rounds) of bidding that raised revenue of over PLN 9 billion (over EUR 2 billion). This paper describes in detail the rules of the Polish 4G auction, analyses bidding behaviour and auction dynamics of the crucial phases of auctions, and presents the final outcomes. It also draws lessons that could help policy makers in Poland and other countries in auction design.