WiMAX系统覆盖率和吞吐量研究

由于802．16e加入了移动性,这就可能造成快衰的损耗,所以同时需要使用闭环功控来补偿衰落。本文将针对802．16e功控方式对WiMAX系统覆盖和吞吐量进行分析。     

Analysis of Frequency Reuse and Throughput Enhancement in WiMAX Systems

The WiMAX (IEEE 802.16e-2005) standard supports fractional frequency reuse concept. To implement this idea, the WiMAX standard has proposed the concept of zones where different frequency reuse factors (FRFs) are employed. Here, each cell/cluster operates with multiple zones where different FRFs are used. The zone of operation for each user can be either permanently fixed or determined dynamically. The dynamic assignment of the zone can potentially utilize the bandwidth efficiently and improve the system throughput. Dynamic zone selection schemes based on the two metrics namely radio distance and bandwidth efficiency are proposed in this paper. The impact of the dynamic zone selection scheme on throughput is studied and compared with the fixed reuse zone schemes.     

LTE终端接收机射频吞吐量测试方法研究

阐述了LTE终端射频一致性测试标准3GPPTS36．521—1中终端接收机特性的吞吐量测试原理和方法,研究了相关的物理层吞吐量判决准则和原理,并对物理层吞吐量判决表的生成做了详细介绍。     

MC—CDMA通信系统接收机的改进

多载波码分多址(M C-CDMA)系统能够支持无线通信业务中的多媒体业务,因此它是很有发展前景的。但是,M C-CDMA的系统性能受到单用户多码自相干和多用户相干的影响。为了解决这种问题,本文引入了一种最小均方误差解相干(MM SE-SIC)接收机,对多用户多径传输情况下的M C-CDMA系统进行了一定的改进。     

An overview of next-generation mobile WiMAX technology - [WiMAX update]

The growing demand for mobile Internet and wireless multimedia applications has motivated the development of broadband wirelessaccess technologies in recent years. Mobile WiMAX has enabled convergence of mobile and fixed broadband networks through a common wide-area radio-access technology and flexible network architecture. Since January 2007, the IEEE 802.16 Working Group has been developing a new amendment of the IEEE 802.16 standard (i.e., IEEE 802.16m) as an advanced air interface to meet the requirements of ITU-R/IMT-advanced for 4G systems, as well as for the next-generation mobile network operators. Depending on the available bandwidth and multi-antenna mode, the next-generation mobile WiMAX will be capable of over-the-air datatransfer rates in excess of 1 Gb/s and of supporting a wide range of high-quality and high-capacity IP-based services and applications while maintaining full backward compatibility with the existing mobile WiMAX systems to preserve investments and continuing to support first-generation products. This tutorial describes the prominent technical features of IEEE 802.16m and the potential for successful deployment of the next generation of mobile WiMAX in 2011+.     

FH—CDMA系统吞吐量的研究

本文提出了一种计算非时槽FH-CDMA系统吞吐量的方法,并进一步证明了当信道业务量μ和频率槽数q趋于无穷,且μ/q保持常数时,时槽FH-CDMA系统的吞吐量与非时槽系统一致,但同步跳频系统的最大吞吐量是异步跳频的两倍。数值结果表明,就吞吐量和系统复杂性而言,采用非时槽系统比采用时槽系统更合适。     

测量用电视系统的一个应用实例

基于视频图像处理的非接触精密测量技术已经成为一种发展趋势,通过介绍一个以该技术为核心的应用实例--靶场用电视测量系统,阐述了该类系统的基本组成及工作原理.     

An Algorithm for Evaluation of Throughput in Multihop Packet Radio Networks with Complex Topologies

The problem of analyzing the thoughput of packet radio networks with realistic topologies is considered. We present an algorithm for the solution of this problem and show that both the memory requirements and running time of this algorithm in practice grow polynomially with the size of the problem. Although in theory both can grow exponentially in the worst case, we offer computational experience with the procedure and show that for realistic topologies where connectivity is related to distance, the rate of growth is quadratic in the number of links. Even for regular grids, which are pathological in their symmetry, the rate of growth is only cubic in the number of links. We thus conclude that the procedure is effective for realistic topologies with up to several hundred nodes.     

WiMAX技术讲座第1讲 WiMAX技术概述

通过不同设备供应商提供的、具有互操作功能的兼容设备,WiMAX可用于提供建设成本低、兼容程度高、互操作性强的BWA解决方案。本文介绍了WiMAX的产生背景,分析了WiMAX的技术优势,给出了WiMAX的参考模型,归纳了国内外应用现状,阐明了WiMAX发展面临的挑战,预测了WiMAX技术的发展趋势。     

基于TD-SCDMA R4路测数据评估HSUPA系统吞吐量的方法研究

本文利用实际TD-SCDMA网络中车载测试得到的测试数据,结合对网络干扰情况的预算及HUSPA系统链路级仿真结果,提出一种评估HSUPA系统吞吐量的方法。该方法考虑了实际的网络拓扑结构及自然传播环境,并且实现方法简单,结果更具有实际意义。     

WiMAX标准体系研究

WiMAX得到了业界的广泛支持,其标准化进程不断推进.本文给出了WiMAX标准化组织IEEE 802.16工作组和WiMAX论坛的组织机构,分析了两大组织之间的相互关系,探讨了WiMAX最新标准化进展,从空中接口标准、一致性标准和共存标准三方面介绍了IEEE 802.16系列标准现状.     

WiMAX组网方案研究

本文研究了基于OFDM技术的WiMAX小区规划方案,给出了各种提高频谱效率的方案;然后对WiMAX与现网的融合进行了分析,给出了紧耦合和松耦合两种方法,并就基于IPv6的WiMAX核心网机制进行了阐述;最后对基站的无线互联方案进行了探讨.     

WiMAX密钥管理方案研究

分析了WiMAX网络物理层和MAC层面临的安全威胁,给出了WiMAX网络安全体系结构;对密钥管理机制中的授权与认证密钥(AK)交换过程以及传输加密密钥(TEK)交换过程进行了详细的介绍。     

基于WiMAX的智能小区系统的设计

为了克服目前主流智能小区系统的缺陷,设计了基于WiMAX的智能小区系统。采用了WiMAX技术构建接入网络系统,不但有效地解决了智能小区系统在复杂地区难以布线的难题,而且简化了系统的维护和升级。介绍了系统的总体设计框架,并重点讲述各个子系统的设计。     

无线接收机结构设计

回顾了无线接收机的发展情况，着重研究了面向SOC的结构，分析了几种典型接收机结构的优缺点，并总结了它们的改进方法。     

基于WiMAX技术的实时视频监控系统设计

分析了WiMAX的技术特点和安全性,探讨了其在实时视频监控系统中应用.提出了基于Inter WiMAX Connection 2250技术的实时视频监控系统设计方案.     

WiMAX系统物理层建模与仿真

基于IEEE802.16d标准,对多天线WiMAX系统的物理层进行了建模和仿真。论述了系统的各种关键模块的模型建立和设计方法,包括信道建模、帧同步、载波同步和信道估计等,并给出了仿真结果和性能分析。通过在衰落信道下的物理路层仿真,对WiMAX系统的具体特点、实现方法以及性能改善有了定量的理解,同时又为多天线技术和各种增强技术在WiMAX系统的深入研究提供了便利平台。     

An Electronic Resuscitation Evaluation System

An electronic system is described that distinguishes and tabulates pressure pulses received from the Resusci-Anne training mannequin during cardiopulmonary resuscitation (CPR). The requirements of this system are in accordance with accepted CPR training programs. Samples of quantitative data gathered during mannequin practice sessions are included. The effectiveness of the system as a teaching aid is investigated, and correlations are made between CPR skills and a trainee's physical attributes.