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《中国无线电》2002,(11):55
依据国际电联有关第三代公众移动通信系统(IMT-2000)频率划 分和技术标准,按照我国无线电频率划分规定,结合我国无线电频谱使 用的实际情况,现将我国第三代公众移动通信系统频率划分有关事宜通 知如下: 一、第三代公众移动通信系统的工作频段为: (一)主要工作频段:频分双工(FDD)方式:1920-1980MHz/2110-2170Hz;时分双工(TDD)方式:1880-1920MHz、2010-2025MHz。 (二)补充工作频率: 频分双工(FDD)方式:1755-1785MHz/1850-1880MHz; 时分双工(TDD)方式:2300-2400MHz,与无线电定位业务共用, 均为主要业务,共用标准另行制定。 (三)卫星移动通信系统工作频段:1980-2010MHz/2170-2200MHz。 相似文献
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时分双工(TDD)是一种现代通信系统常用的双工方式,在移动通信系统中用于分离接收与发送信道(或上下行链路)。如图1所示,在TDD方式的移动通信系统中,接收和发送使用同一频率载波的不同时隙作为信道的承载,用时间来保证接收与发送信道的分离。而传统的频分双工(FDD)方式的移动通信系统的接收和发送使用分离的两个对称频率信道承载,用频段来保证接收与发送信道的分离。[第一段] 相似文献
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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. 相似文献
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日前,工业和信息化部下发《关于国际移动通信系统(IMT)频率规划事宜的通知》,正式发布了我国2.6GHzIMT(包括IMT-2000、IMT-Advanced)频率规划,将IMT核心频段2500MHz~2690MHz总共190MHz带宽的频率资源规划为时分双工(TDD)方式的工作频率,供TD-LTE使用。业界人士普遍认为,2.6GHz频率规划的适时出台,显 相似文献
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本刊讯(记者马斌)日前,工业和信息化部发布了《关于国际移动通信系统(IMT)频率规划事宜的通知》(以下简称《通知》),公布了我国2.6GHz频段IMT频率规划。《通知》规定,2500MHz~2690MHz频段为时分双工(TDD)方式的IMT系统工作频率。该频率规划的发布,充分体现了我国政府主管部门"以支持TD产业发展为主导、兼顾FDD 相似文献
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本文对DS-SS CDMA蜂窝移动通信中的功率控制问题进行了分析,在对信号传输的信道因素的分析基础上,针对频分双工和时分双工两种不同系统的特点,分别提出了两种功率控制方案,从而扩大了系统容量,改善了系统性能。 相似文献
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Holma H. Heikkinen S. Lehtinen O.-A. Toskala A. 《Selected Areas in Communications, IEEE Journal on》2000,18(8):1386-1393
The air interface of the UMTS Terrestrial Radio Access (UTRA) covers both a frequency division duplex (FDD) part for the paired bands and a time division duplex (TDD) part for the unpaired bands of the UMTS spectrum. The Universal Mobile Telecommunication System (UMTS) is the 3rd-generation mobile communication system. This paper presents an interference evaluation of the UTRA TDD. Since both uplink and downlink share the same frequency in TDD, the signals of the two transmission directions can interfere with each other. This interference can occur between two mobile stations or between two base stations within one carrier or between two operators. The interference between uplink and downlink is evaluated by system simulations. Synchronization and coordination requirements of UTRA TDD are evaluated based on the results 相似文献
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ZHANG Ying-hai WANG Wei-dong DONG Yu ZHOU Kai-jie Information Electronics Technology Laboratory Beijing University of Posts Telecommunications Beijing China 《中国邮电高校学报(英文版)》2006,13(4):13-18
1 Introduction With the development of mobile communications, the application of future high rate mobile communications network (4G) has been placed on the agenda. From technica perspective, 4G will support high transmission rate and capacity; in the view… 相似文献
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目前2G通信技术基本已经停用,3G通信技术得到普遍应用,4G通信技术也已经得到广泛推广和使用,通信行业的研究焦点从4G通信技术迅速转移到5G通信技术.本文结合5G通信技术的未来展望,分析了具有发展前景的大规模MIMO技术、毫米波频段移动通信技术、同频全双工技术三项面向5G通信的射频关键技术. 相似文献
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In this letter, we propose an overlaid hybrid division duplex (HDD) concept for cellular systems which divides a cell into inner and outer regions and utilizes the merits of both time division duplex (TDD) and frequency division duplex (FDD). The proposed system can take advantage of both TDD and FDD without handover between two duplex schemes. Moreover, it is shown that the proposed HDD system outperforms the conventional TDD or FDD system with mobile relay stations when the synchronization issue is considered in orthogonal frequency division multiple access systems. Thus, the proposed overlaid HDD can be considered as a new framework for future cellular systems. 相似文献
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TD-LTE通信技术采用了国际上先进的LTE通信技术体制,以TDD双工方式为特征,是我国自主创新的TD-SCDMA的演进技术,是下一代移动通信与宽带无线接入融合的典范,也是未来宽带移动通信的主流标准之一。结合水利通信业务的发展,文中分析了TD-LTE的关键技术及特点,并给出了基于TD-LTE技术的网络架构,同时重点介绍了其在水利防汛中的应用。 相似文献
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With the growing popularization of mobile communication services, a growing demand for better Quality of Service (QoS) arises from the subscribers. An uninterrupted service provided with the network after a node failure is also expected from operators. To achieve these, duplex backup and even multiple backup functions have been gradually introduced into the network. Among redundancy technologies, dual home and IuFlex are more successful. Dual home is a typical duplex backup system with activation of the standby server after the host server failure. IuFlex is one of the multiple backup technologies with overhead transference to other node in switching pool after single switching node failure. 相似文献
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未来移动通信系统中的无线资源管理 总被引:10,自引:3,他引:7
文章结合当前正在研究的后3代(B3G)、第4代(4G)移动通信系统的发展和处于运营及推广阶段的第3代移动通信系统,分析了未来移动通信系统中无线资源管理系统的关键技术,探讨了多体制标准下的无线通信网络和多种业务情况下的无线资源管理的研究方向。 相似文献
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Salim Kahveci 《Journal of Communications Technology and Electronics》2017,62(10):1130-1135
There has been active research worldwide to develop the next generation, i.e., fifth generation, wireless network. Next generation mobile communication networks are broadening their spectrum to higher frequency bands (above 6 GHz) to support a high data rate up to multigigabits per second. This work examines how to substantially improve energy efficiency for next fifth generation mobile communication systems. It is depicted how by limited exchange of information between neighboring base stations it is possible to maintain quality of service, over a range of traffic loads, while enabling inactive base stations to sleep. Performance of distributed energy efficient topology management schemes are compared against the system without topology management. Performance evaluation is examined using both analytical and simulation based models. Extensive numerical results show that the schemes deliver a significant energy reduction in energy consumption in the mobile network systems. 相似文献
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随着移动通信技术的快速发展,移动通信电源的功能也得到了不断的创新和完善,当前的移动通信电源系统已经具备了较好的安全性和稳定性,但随着移动通信用户要求的不断提高,和移动通信业务的快速发展,移动通信电源系统的可靠性得到了更为广泛的重视,如何通过技术手段或管理手段实现移动通信电源系统可靠性的提升,已经成为广大技术人员所关注的重要课题。本文在介绍移通信电源系统构成的基础上,对其可靠性的内涵进行了阐述,并就如何通过合理的技术与管理手段来提升移动通信电源系统可靠性提出了一些可行的方法,以供参考。 相似文献