正交频分复用OFDM技术的研究

I目录摘要...........................................................................................................................................IIIAbstract..........................................................................................................................................V第一章绪论........................................................................................................................-1-1.1引言..........................................................................................................................-1-1.2OFDM的提出和发展...............................................................................................-2-第二章OFDM原理...............................................................................................................-5-2.1引言............................................................................................................................-5-2.2多载波调制................................................................................................................-5-2.3并行传输体制概述....................................................................................................-9-2.4OFDM基本原理.....................................................................................................-10-2.5OFDM系统性能特点.............................................................................................-13-2.6本章小结..................................................................................................................-14-第三章基于OFDM的无线局域网....................................................................................-17-3.1引言........................................................................................................................-17-3.2物理层结构..............................................................................................................-17-3.3OFDMPLCP子层...................................................................................................-18-3.4仿真分析..................................................................................................................-21-3.4.1SystemView软件简介...................................................................................-21-3.4.2无线局域网的实现框图................................................................................-22-3.4.3采用SystemView进行仿真分析。..............................................................-22-3.5本章小结..................................................................................................................-24-第四章总结与展望............................................................................................................-25-致谢......................................................................................................................................-27-参考文献..................................................................................................................................-29-IIIII正交频分复用OFDM技术的研究摘要OFDM（OrthogonalFrequencyDivisionMultiplexing）即正交频分复用，是一种特殊的多载波调制技术。OFDM全称为正交频分复用（OrthogonalFrequencyDivisionMultiplexing），是一种新型的高效的多载波调制技术，它能够有效地对抗多径传播，使受到干扰的信号能够可靠地接收。经过几十年的开发之后，OFDM/COFDM不但被广泛地应用于高速数字通信中，而且已扩展到其他领域。同时现代数字信号处理技术和超大规模专用集成电路（VLSI）的发展也使得快速傅立叶变换的实现变的更加容易，使该技术的实现费用更趋实际，为以后OFDM广泛应用于通信领域开辟了道路。论文首先研究了OFDM理论，重点分析了在频率选择性衰落信道中OFDM技术解决码间干扰问题的原理；总结分析了基于OFDM的无线局域网，利用SystemView对基于OFDM无线局域网系统进行了仿真，并对可能影响结果的信噪比、调制映射和信道进行了分析，结果符合预期。关键词：正交频分复用，多载波调制，信噪比，调制映射IVVTheresearchoftheOrthogonalFrequencyDivisionMultiplexingOFDMtechnologyAbstractOFDM(OrthogonalFrequencyDivisionMultiplexing)thatisOrthogonalFrequencyDivisionMultiplexing,isaspecialmulti-carriermodulationtechnique.OFDMfullnameOrthogonalFrequencyDivisionMultiplexing(OrthogonalFrequencyDivisionMultiplexing),isanewtypeofhighlyefficientmulti-carriermodulationtechnique,itcaneffectivelyfightagainstmulti-pathcommunication,sothatthesignalinterferencecanreliablyreceive.Afterseveraldecadesofdevelopmentafter,OFDM/COFDMhasbeenwidelyusedinhigh-speeddigitalcommunications,andhasspreadtootherareas.Atthesametimemoderndigitalsignalprocessingtechnologyandultra-large-scaleapplicationspecificintegratedcircuits(VLSI)alsomakesthedevelopmentofthefastFouriertransformtoachievechangemoreeasilysothatthecostofthetechnologytoachievemorepractical,forthefutureOFDMwidelyusedinthefieldofcommunicationopenTheroad.AtthefirstthePapersResearchtheOFDMtheory,andonthefocusofthefrequencyselectivefadingchannelOFDMtechnologytosolvetheinterferenceproblembetweenthecodeofprinciple;summaryofOFDM-basedwirelesslocalareanetwork,usingtheSystemViewOFDM-basedwirelessLANsystemsimulationandMayaffecttheoutcomeofthesignaltonoiseratio,modulationandchannelmappingananalysisoftheresultsinlinewithexpectations.Keywords：（OFDM）OrthogonalFrequencyDivisionMultiplexing,Multi-carriermodulation,SNR,Modulationmapping.VI-1-第一章绪论1.1引言个人通信是人类通信的最高目标，它是用各种可能的网络技术、实现任何人在任何时间、任何地点与任何人进行任何种类的信息交换。这种境界使用户彻底摆脱了终端的束缚。实现这种境界最基本要求就是满足用户的移动性。为了实现无线个人通信，工业界、学术界和各种标准化组织都在进行广泛深入的研究和讨论。而这些讨论和研究的焦点无非是要面对系统的容量、新道的分配方法、设计的复杂性和系统性能的折衷。就移动通信而言，在信道中广泛存在着三类扩散。这就带来的三种