research+on+synchronization+for+ofdm+system

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1、哈尔滨工程大学硕士学位论文ResearchonSynchronizationforOFDMSystem姓名：FellouhSfiane[思凡]申请学位级别：硕士专业：信号与信息处理指导教师：Prof.MaHuiZhu[马惠珠]201103ResearchOilSvnchronizaIionfor0FDMSystem摘要相干解调经常应用于正交载波频分复用(OFDM)系统以达到更好的传输性能，但同时要求进行准确地同步。尽管如此，传统的添加前导训练序列的方法大幅地增加了对带宽的占用。在本文中，提出了一种并行的训练序列结构用于对OFDM系统进行同步，该方法将训练序列并行地加到

2、信号流上。本文中，我们将采用m序列作为训练序列对OFDM系统进行高效地频偏估计，在时域上将两段重复的m序列直接加到OFDM符号上，利用m序列优秀的自相关性完成系统的频率同步，与传统的方法相比有效性更高。理论分析与仿真实验结果一致，本文提出的方法可以用于OFDM系统的频率同步。本文还提出了一种新的训练序列，该序列可以应用于高功率信号传输中，称为零子载波叠加训练序列。最后，将两种训练序列应用于系统同步中，对其进行仿真比较。关键词：OFDM；并行训练序列结构；CAZAC／m序列；ML估计算法AbstractCoherentdemodulationisusuallyadopt

3、edinorthogonalfrequencydivisionmultiplexing(OFDM)systemtoachievebetterperformance．Itmeansaccuratesynchronizationaxeneeded．However,traditionalpreambletrainingsequencedecreasesubstantiallybandwidthutilization．Inthisthesis，asuperimposedtrainingschemeforsynchronizationisproposedforOFDMsyste

4、m，wheretrainingsequencearesuperimposedontodatastreamNotethatweaddedthem-sequenceandguardintervalinthetimedomainOFDMsignal．Inthisthesis，weproposeandanalyzeallefficientfrequencyoffsetsynchronizationmethodbasedonm—sequenceofOFDMsystem．Repeatedm-sequenceissuperimposeddirectlytoOFDMframesint

5、hetimedomain．Byutilizingtheautocorrelationcharacteristicsofm-sequence，efficientsynchronizationc锄beachievedwithoutimposingadditionalcomplexity．The仃equencyoffsetestimatorarederivedbasedonthemaximumlikelihoodcriterionboththeoreticalandsimulatedresultsarepresentedtoverifytheproposedfrequenc

6、ysynchronizationmethod．Alsoanewtrainingsequenceisproposedinthisthesiswecallitsuperimposedtrainingsequencewithzeroaddeditwasmadetoovercometheproblemofhi【ghpowerofthetransmittedsignal．SimulationwasmadetocomparebetweenthetwotrainingsequenceKeyword：OFDM；Superimposedtrainingsequence；CAZAC／ms

7、equence，MLalgorithm1．1IntroductionChapter1IntroductionThedemandforhighdatarateserviceshasbeenincreasingveryrapidlyandthereisnoslowdowninsight．Almosteveryexistingphysicalmediumcapableofsupportingbroadbanddatatransmissiontoourhomes，officesandschoolshasbeenorwillbeusedinthefuture．