eIMTA技术中的干扰管理策略

随着异构网络的兴起,业务自适应（TA：traf原fic adaptation）技术成为TD-LTE技术增强的一个重要方向。如何有效地控制业务自适应技术带来的交叉时隙干扰,成为当前研究的热点。文章分析了目前比较主流的干扰控制方案,即基于小区分簇的干扰控制方案（CCIM）和基于上行功控的干扰控制方案（ULPC）,提供了评估结果,并针对异构网络场景的干扰管理方法进行了初步的探讨。研究证明CCIM和ULPC可以有效的控制干扰。     

TD-LTE系统切换技术的研究

文章介绍时分同步码分多址长期演进(TD-LTE)中的无线资源管理(RRM)的关键技术,及TD-LTE系统的切换流程和协议设计。针对TD-LTE系统现存的一些迫切需求,提出了一种基于切换滞后差值(HOM)和触发时间(TTT)的切换算法,研究了在切换中HOM和TTT对系统性能的影响。动态仿真结果表明随着HOM和TTT的增长,在系统吞吐量没有明显下降的基础上,总切换次数有了大幅度的减少,降低了系统信令的交互频率,节省了系统资源并提高了切换效率。     

第三代移动通信中TDD和FDD共存的干扰分析

详细分析了3G中TDD以及TDD与FDD之间的各种干扰,建立了一些可用于3G系统性能研究的干扰模型,并提出了一些有效的建议来避免或减少系统中的干扰。     

TD-LTE业务和终端现状及发展趋势

无线通信技术发展突飞猛进,全球首个具有自主知识产权的准4G无线宽带网络TD-LTE也已在上海世博会园内开通,这标志着我国TD通信产业的一个新起点。相对而言,目前整个TD-LTE产业链上,业务和终端还处于发展阶段。本文立足于这二者的现状,分析业务和终端还需做的改进,并探讨其发展的趋势。     

一种消除TD-SCDMA系统小区间干扰的方法

时分-同步码分多址(TD-SCDMA)系统采用的扩频码码长最大为16,当邻小区用户处于2小区边缘时会对本小区造成较大的干扰。针对上行链路提出了一种新的干扰消除方法:串行干扰消除-联合检测(SIC-JD)。该方法采用复杂低的SIC对上行链路中的小区间干扰进行消除,对于小区内干扰和残留的小区间干扰采用联合检测进行消除。3GPP case1信道下的仿真结果显示了此方法能够有效消除小区间和小区内干扰,提高接收机性能。     

一种LTE-A系统上行传输模式自适应算法

LTE-A（增强型长期演进）系统上行引入了多天线传输技术来解决终端天线较少的问题。在这种技术背景下,设计了一种上行传输模式自适应方法以提高系统性能。从传输模式间自适应、单双流自适应和MU-MIMO（多用户多输入多输出）与单天线传输之间的自适应三个方面进行了论述。系统级仿真表明,基站根据信道条件的变化选择适当的传输方式可以有效地降低用户误码率,提高系统吞吐量。     

TDD的关键技术及其应用前景

本文从时分双工(TDD)方式的相关关键技术、优缺点以及在未来移动通信系统中的地位等方面,对采用TDD方式的移动通信系统的特点与发展趋势进行了深入分析,并给出了一些发展建议.     

LTE宽带无线公网在智能电网中的性能分析

配网通信技术是DA（配网自动化）管理系统的关键技术之一。文章首先分别讨论了以光纤通信、电力线载波技术和蜂窝无线公网技术承载DA业务的优劣;然后在此基础上进一步阐述了基于第四代移动通信技术LTE（长期演进）系统的组网方案;最后,针对DA业务中低压集抄业务的两种典型应用场景（周期汇报和供电恢复）仿真评估了LTE在FDD（频分双工）以及TDD（时分双工）模式下承载DA业务的可行性。仿真结果表明,对于周期性汇报居民用电业务,LTE FDD系统和LTE TDD系统均能满足该项业务QoS（服务质量）需求,而LTE FDD系统更适合承载此类业务。在居民区供电中断后恢复场景下,无论是LTE FDD系统还是LTE TDD系统,在无线侧都需要进一步的优化方案,以解决大量低压集抄终端同时接入时产生拥塞的问题。     

自适应遗传算法下的NOMA用户动态分簇

NOMA(Non-orthogonal Multiple Access,NOMA)系统中的用户分簇策略对系统性能有着极大的影响。该文主要研究NOMA下行链路的用户动态分簇问题,其目的是最大化系统总吞吐量。与大多数文章不同,该研究对簇中用户数以及簇个数都没有限制。遗传算法可用于优化NOMA网络中的用户动态分簇,但标准遗传算法存在收敛速度慢且容易陷入局部最优的问题。基于此,该文将自适应调节参数的改进遗传算法用于用户的动态分簇,来改善上述问题。仿真结果表明,该算法相比于穷举搜索能够有效降低求解复杂度,且系统性能明显优于固定簇分配算法及自适应配对策略下的系统性能。      

TD-LTE-Advanced技术、标准与产业的发展及展望

从TD-SCDMA演进角度,即TDD标准演进角度,介绍了TD-LTE-Advanced的关键技术、标准演进以及TD-LTE的产业链发展与全球商用情况,分析其商用对我国集成电路产业发展的带动作用,并对TD-LTE未来产业发展、技术与标准演进做出了展望,为推进TD-LTE商用、后续技术与标准演进研究提供相关参考。     

干扰控制技术在LTE家庭基站中的应用

家庭基站是近年新兴的室内覆盖技术,能以较低的功率为用户提供高速率高带宽的服务,是新一代移动网络与固定网络的一种融合方式。文章主要针对家庭基站和现有宏蜂窝基站组成的异构网络的几种典型干扰场景,从上、下行功率控制和无线资源干扰协调三方面,对家庭基站干扰管理的基本原理进行了说明,并介绍了基于干扰抑制的上、下行功率控制和干扰协调等典型的干扰管理技术。     

An Efficient Adaptive Cell Sectoring Technique for Non-Uniform Traffic in DS-CDMA Systems

Cell sectorization has been shown as a promising technique to improve the overall capacity in direct sequence code division multiple access (DS-CDMA) systems. It has been further demonstrated that the use of adaptive antenna arrays with dynamic cell sectoring is particularly suitable for non-uniformly distributed users. In this paper, we first re-formulate cell sectoring into an optimization problem and solve it with dynamic programming algorithm. We next show that this has two major practical drawbacks: the complexity and oscillation of users between neighboring sectors. We then present an efficient Cluster-based Sectoring (CS) algorithm for adaptive cell sectorization to overcome these two inefficiencies: Firstly, the computation complexity of CS algorithm is much lower than that of the optimal sectoring algorithm. In particular under high-density case, the complexity is bounded and does not depend on the number of users in a cell; Secondly, the CS algorithm maintains the excellent property of avoiding sector boundaries frequently crossing those users closely located within short angular distances. In addition, we also investigate the support for multi-rate applications with the proposed CS algorithm. Through extensive experimental study, we find that the performance of proposed CS scheme obtains comparable performance with greatly reduced complexity when comparing to the optimal solution. Jihui Zhang received her B.S. degree from Computer Science Department at Fudan University, China. She is working toward the Ph.D. degree in the Computer Science Department at Hong Kong University of Science and Technology. Her research interests include the resource management in CDMA cellular networks and wireless ad-hoc networks. Bo Li received his B. Eng. (summa cum laude) and M. Eng. degrees in the Computer Science from Tsinghua University, Beijing in 1987 and 1989, respectively, and the Ph.D. degree in the Electrical and Computer Engineering from University of Massachusetts at Amherst in 1993. Between 1993 and 1996, he worked on high performance routers and ATM switches in IBM Networking System Division, Research Triangle Park, North Carolina. Since 1996, he has been with the Department of Computer Science, Hong Kong University of Science and Technology. He has held an adjunct researcher position at the Microsoft Research Asia (MSRA), Beijing, China. His research interests are on adaptive video multicast, packet scheduling and dynamic routing in optical networks, resource management in mobile wireless systems, scheduling and energy efficient routing in ad hoc networks, across layer design for sensor networks, and content distribution and replication. He has published 70 some journal papers and held several patents in above areas. He received the Outstanding Oversea Young Scientist Award from National Natural Science Foundation of China in 2004. He has been on editorial board for 16 journals and involved in organizing over 40 conferences, esp. IEEE Infocom since 1996. He was the Co-TPC Chair for IEEE Infocom 2004. Jiangchuan Liu received the B.Eng degree (cum laude) from Tsinghua University, Beijing, China, in 1999, and the Ph.D. degree from The Hong Kong University of Science and Technology in 2003, both in computer science. He is currently an assistant professor in the School of Computing Science, Simon Fraser University, BC, Canada, and was an assistant professor at The Chinese University of Hong Kong from 2003 to 2004. He was a recipient of Microsoft research fellowship (2000), a recipient of Hong Kong Young Scientist Award (2003), and a co-inventor of one European patent (granted) and two US patents (pending). He won first-class honors in several regional and national programming contests. His research interests include Internet architecture and protocols, media streaming, wireless ad hoc networks, and service overlay networks. He serves as TPC member for various networking conferences, including IEEE INFOCOM’04 and ‘05. He was TPC Co-Chair for The First IEEE International Workshop on Multimedia Systems and Networking (WMSN’05), Information System Co-Chair for IEEE INFOCOM’04, and a guest-editor for ACM/Kluwer Journal of Mobile Networks and Applications (MONET), Special Issue on Energy Constraints and Lifetime Performance in Wireless Sensor Networks. He is a member of IEEE and IEEE Communications Society, and an elected member of Sigma Xi.     

电信网络话务流量自动控制技术的研究

电信网络话务流量自动控制是实现网络自动化管理的内容之一。在分析话务理论的基础上 ,提出了基于本地网网络管理与集中监控系统平台的话务流量自动控制技术 ,并详细介绍了系统的模型和软件流程 ,通过具体的工程应用说明该系统有一定的可行性和实用性。     

OTT TV业务流量经营及关键技术应用

介绍了以OTT TV业务系统为基础,通过移动终端结合跨屏内容强关联、O2O服务等业务方式进行流量经营,进而实现OTT TV业务价值的增值与转移.详细描述了利用现有内容制作、多屏协议、内容关联等技术,通过用户间的分享实现内容组织、业务服务、营销推广自组织的技术方案.     

应用流量管理技术在有线宽频网络中的应用

有线宽频网络运营商在网络运营中，会因为应用流量的不规范应用而对业务造成极大影响甚至带来损失，探讨把应用流量管理技术引进有线宽带网络，通过该技术对应用流量的智能识别、分类、控制等实现对网络流量的管理，进一步提高带宽资源的利用率。     

认知无线电的关键技术研究

认知无线电是一种通过与其运行环境交互而改变其发射参数提高频谱利用率的新的智能技术.论文首先分析了认知无线电提出的现实意义,然后在描述认知无线电的概念和模型的基础上,结合已有的研究,讨论了频谱环境感知、干扰温度、频谱汇聚共享、动态频谱管理等关键问题.最后,基于前面的研究提出了对认知无线电未来的展望.     

基于强化学习的城市交通区域协调控制研究

交通控制系统是一个复杂的巨系统,传统的建模和控制方式难以获得较好的控制效果.文章针对区域协调控制中难以建立精确数学模型的特点,引入了强化学习,提出了基于强化学习的无模型区域协调控制算法.采用微观交通仿真软件对算法进行了仿真实验,与Webster定时控制进行对比,实验结果表明:强化学习算法取得较好的效果.     

EPS系统中业务流模板研究

为了更好地保证端到端的QoS机制,为用户提供差异化服务体验,EPS系统支持通过EPS承载对分组数据进行传送。通过对业务流模板(TFT)的研究,了解UE中上行分组过滤器(UL_PF)与EPS承载的关系,研究上行IP分组包与分组过滤器(PF)的匹配过程,给出一种PF与IP分组包之间的匹配实现方案,最终实现IP数组在EPS承载上传输。     

基于认知无线电技术的802.22标准

认知无线电技术能够监测到无线电环境中已存在的用户,同时监控频谱资源的使用情况,并能动态地调整各无线用户的传输参数,从而提高频谱资源的利用率。基于认知无线电技术的802.22标准要求在不损害已有电视设备服务的前提下,使用电视频带为非授权用户提供廉价的无线接入服务。对认知无线电技术和802.22标准结构进行了深入分析,并讨论了一些重点需要解决的问题。