网络优化的主要目标是达到所承建的TD-SCDMA 网络服务质量达到或超过商业合同标准,切实为用户打造一个TD-SCDMA 的精品网络。
上传时间: 2013-12-28
上传用户:asasasas
多用户通信实现的本质就是把可用的资源划分成多个相互正交的资源(互不重叠,或互不相同,或互不干扰的资源)频域资源划分 —FDMA传统的FDMA的频率间隔最小为2× 1/T,“资源互不重叠,互不相同” OFDM频率间隔为1/T,资源部分重叠,但互不干扰; 时间资源划分 —TDMA,资源互不重叠,互不相同; 码字资源划分 —CDMA,资源重叠,但互不干扰;
标签: TD-LTE
上传时间: 2013-11-24
上传用户:liglechongchong
一致性认证:TD-SCDMA早期缺乏国际化的组织对终端进行一致性测试和验证、缺乏一致性测试仪表等因素,导致终端质量参差不齐,为兼顾终端能力部分网络新功能无法正常投入现网运营 产业投入:市场缺乏类似Iphone具有较大市场吸引力的高端终端、性价比较高的低端终端;部分国际上具有雄厚实力的芯片和终端制造商尚未推出TD-SCDMA产品
上传时间: 2013-11-23
上传用户:cc1915
提出了一种应对CDMA系统中有界干扰的鲁棒自适应功率控制算法.仿真结果表明,与传统的功率控制算法相比,该算法性能优越,可以使用户获得更高的信噪比和较低的发射功率,且系统容量得到了提高.
上传时间: 2013-11-02
上传用户:yimoney
无线网络的建设涉及到网络规划、网络优化仿真等工作,需要用到通讯和 CDMA 方面的基础知识。本教材将对部分通讯基础知识、网络规划优化流程、CDMA 部分基础技术、中兴系统等内容进行介绍,为顺利开展网络规划优化工作提供指导。本教材不包括中兴自主开发的测试分析软件的介绍,相关内容参见相应用户手册。
上传时间: 2013-12-18
上传用户:zoudejile
文章介绍了CDMA 系统无线资源的软切换的管理与控制,包括切换类型、切换策略、无线网络设计对网络的影响、切换参数的设置、搜索窗参数设置、邻小区参数设置以及无线网络优化等内容。
上传时间: 2013-10-31
上传用户:daguda
Single-Ended and Differential S-Parameters Differential circuits have been important incommunication systems for many years. In the past,differential communication circuits operated at lowfrequencies, where they could be designed andanalyzed using lumped-element models andtechniques. With the frequency of operationincreasing beyond 1GHz, and above 1Gbps fordigital communications, this lumped-elementapproach is no longer valid, because the physicalsize of the circuit approaches the size of awavelength.Distributed models and analysis techniques are nowused instead of lumped-element techniques.Scattering parameters, or S-parameters, have beendeveloped for this purpose [1]. These S-parametersare defined for single-ended networks. S-parameterscan be used to describe differential networks, but astrict definition was not developed until Bockelmanand others addressed this issue [2]. Bockelman’swork also included a study on how to adapt single-ended S-parameters for use with differential circuits[2]. This adaptation, called “mixed-mode S-parameters,” addresses differential and common-mode operation, as well as the conversion betweenthe two modes of operation.This application note will explain the use of single-ended and mixed-mode S-parameters, and the basicconcepts of microwave measurement calibration.
上传时间: 2014-03-25
上传用户:yyyyyyyyyy
用二端口S-参数来表征差分电路的特性■ Sam Belkin差分电路结构因其更好的增益,二阶线性度,突出的抗杂散响应以及抗躁声性能而越来越多地被人们采用。这种电路结构通常需要一个与单端电路相连接的界面,而这个界面常常是采用“巴伦”器件(Balun),这种巴伦器件提供了平衡结构-到-不平衡结构的转换功能。要通过直接测量的方式来表征平衡电路特性的话,通常需要使用昂贵的四端口矢量网络分析仪。射频应用工程师还需要确定幅值和相位的不平衡是如何影响差分电路性能的。遗憾的是,在射频技术文献中,很难找到一种能表征电路特性以及衡量不平衡结构所产生影响的好的评估方法。这篇文章的目的就是要帮助射频应用工程师们通过使用常规的单端二端口矢量网络分析仪来准确可靠地解决作为他们日常工作的差分电路特性的测量问题。本文介绍了一些用来表征差分电路特性的实用和有效的方法, 特别是差分电压,共模抑制(CMRR),插入损耗以及基于二端口S-参数的差分阻抗。差分和共模信号在差分电路中有两种主要的信号类型:差分模式或差分电压Vdiff 和共模电压Vcm(见图2)。它们各自的定义如下[1]:• 差分信号是施加在平衡的3 端子系统中未接地的两个端子之上的• 共模信号是相等地施加在平衡放大器或其它差分器件的未接地的端子之上。
上传时间: 2013-10-14
上传用户:叶山豪
Agilent AN 154 S-Parameter Design Application Note S参数的设计与应用 The need for new high-frequency, solid-state circuitdesign techniques has been recognized both by microwaveengineers and circuit designers. These engineersare being asked to design solid state circuitsthat will operate at higher and higher frequencies.The development of microwave transistors andAgilent Technologies’ network analysis instrumentationsystems that permit complete network characterizationin the microwave frequency rangehave greatly assisted these engineers in their work.The Agilent Microwave Division’s lab staff hasdeveloped a high frequency circuit design seminarto assist their counterparts in R&D labs throughoutthe world. This seminar has been presentedin a number of locations in the United States andEurope.From the experience gained in presenting this originalseminar, we have developed a four-part videotape, S-Parameter Design Seminar. While the technologyof high frequency circuit design is everchanging, the concepts upon which this technologyhas been built are relatively invariant.The content of the S-Parameter Design Seminar isas follows:
标签: S参数
上传时间: 2013-12-19
上传用户:aa54
s参数计算器,S11,S12,S22,S21的参数,一算变知,非常方便。
上传时间: 2013-11-21
上传用户:432234