MIMO-OFDM信道估计的算法研究

大学毕业设计(论文)IMIMO-OFDM信道估计的算法研究目录摘要............................................................................................................................................IIAbstract.........................................................................................................................................III第1章绪论..............................................................................................................................-1-第2章MIMO与OFDM的基本理论....................................................................................-3-2.1OFDM系统简介...............................................................................................................-3-2.1.1OFDM的发展历史...................................................................................................-3-2.1.2OFDM的基本原理...................................................................................................-5-2.1.3OFDM实现的关键技术...........................................................................................-8-2.1.4OFDM技术的优缺点.............................................................................................-10-2.2MIMO的系统描述.........................................................................................................-11-2.3MIMO-OFDM系统........................................................................................................-13-2.3.1MIMO－OFDM系统模型.....................................................................................-13-2.3.2MIMO－OFDM系统关键技术..............................................................................-16-第3章MIMO-OFDM信道估计的算法研究........................................................................-19-3.1无线信道的特征.............................................................................................................-19-3.2信道估计的常用方法.....................................................................................................-21-3.2.1导频辅助信道估计..................................................................................................-22-3.2.2信道的盲估计技术.................................................................................................-22-3.2.3MIMO-OFDM盲信道估计技术的优点.................................................................-24-3.3基于子空间的盲信道估计.............................................................................................-24-3.4仿真结果及性能分析分析.............................................................................................-27-第四章总结与展望................................................................................................................-35-4.1总结.................................................................................................................................-35-4.2展望.................................................................................................................................-35-参考文献..................................................................................................................................-36-致谢.................................................................................................................错误!未定义书签。附录..........................................................................................................................................-37-大学毕业设计(论文)IIMIMO-OFDM系统的信道估计仿真与实现摘要在解决未来无线移动通信系统要求的高速数据传输及频带利用率的问题上，MIMO-OFDM系统表现出良好的性能，能够有效提高无线通信系统的传输速率和容量，抵抗多径衰落和码间干扰。信道估计是MIMO-OFDM通信系统中的关键技术之一。盲信道估计方法从根本上避免了训练序列的使用，可以自启动收敛并防止失锁情况。它提供了比单独使用训练序列时更好的系统性能。本文运用MATLAB软件对MIMO-OFDM系统进行基于子空间的盲信道估计算法的仿真，绘制了均方误差和平均偏差随信噪比变化的关系曲线。仿真结果表明了信道估计算法能有效地减少信道估计错误，使系统达到更高信道利用率。关键词:MIMO-OFDM系统,盲信道估计，子空间算法，MATLAB仿真‘大学毕业设计(论文)IIIImplementationofSimulationonMIMO-OFDMSystemChannelEstimationAbstractInordertosolvetheproblemthatwirelessmobilecommunicationsystemsrequirehigh-speeddatatransferandbandwidthefficiency,MIMO-OFDMsystemshasrecentlyshowedhighperformance,whichcannotonlyeffectivelyenhancethetransmissionrateandcapacityofthewirelesscommunicationsystembutalsocombatmultipathfadingandinterference.ThechannelestimationisoneofthemostimportanttechnologiesinMIMO-OFDMsystems.Blindchannelestimationmethodsavoidthefundamentaluseoftrainingsequences,andcanbeself-startingtopreventlossoflockconvergence.Itcanprovidebetterperformancethanwithonlytraining.Inthispaper,weuseoftheMATLABsoftwareforMIMO-OFDMsystemfortheblindsubspace-basedchannelestimation,anddrawsthechangecurveswhichaboutthemeansquareerrorandtheaveragedeviation.Thesimulationresultsshowthatthechannelestimationalgorithmcaneffectivelyreducethechannelestimationerror,systemscanachievehigherchannelutilization.Keywords:MIMO-OFDMsystems,blindchannelestimation,Sub-spacealgorithm,MATLABsimulation大学毕业设计(论文)-1-第1章绪论无线通信作为新兴的通信技术在日常生活中的作用越来越大。近年来，无线局域网技术发展迅速，但无线局域网的性能、速度与传统以太网相比还有一定距离，因此如何提高无线网络的性能和容量日益显得重要。随着蜂窝移动通信、宽带无线接入技术、多媒技术的迅速发展，简单的语音业务、低速数据业务已经不能满足人们的需求，电信运营商需要开发更多新的增值业务来吸引与保留顾客，如多媒体通信、LBS(位置业务)、游戏、移动视频、电视业务。由于单载波技术存在严重的ISI并且均衡不易实现复用，CDMA扩频调制技术的扩频增益低、抗噪声能力下降，不能满足宽带高速业务的要求。为了能在复杂的电磁环境和紧缺的频谱资源条件下，实现高速率、高质量、高效率的数据传输，必须采用更有效的无线传输技