全双工流星余迹通信系统的实现与测试VIP免费

题（中、英文）目全双工流星余迹通信系统的实现与测试ImplementationandTestforFullDuplexMeteorBurstCommunicationSystem摘要流星余迹通信就是利用流星电离余迹对无线电波的反射和散射作用来进行通信，是一种理想的应急通信手段。本文选题来源于国家“十一五”重点项目，国家自然科学基金(60672129)。流星余迹通信作为一种突发的通信方式，具有抗干扰，不易被截获，单跳通信距离远等特点。然而，流星余迹通信只有在流星出现，在天线照射区内时才能被利用，并且一个流星余迹的持续时间非常短，通常在300~500毫秒，因此提高数据通过率是流星余迹通信要解决的一个主要问题。由于流星信道中存在多径干扰，为了提高通信性能，我们给出了基于OFDM传输的全双工流星余迹通信系统。同时考虑到流星余迹的快衰落特性，采用了自适应变速率方法。为了降低系统的接收门限，提高信道利用率，提出了一种基于OFDM信号功率检测的模拟与数字相结合的自动增益控制方法。最后，通过实验室内和野外线路实验的测试结果表明，这些技术有效地提高了数据通过率。关键词：流星余迹通信OFDM全双工自动增益控制自适应变速AbstractMeteorBurstCommunication(MBC)isaperfectemergencycommunicationmethod,whichusesreflectionanddispersionofradiowavetothemeteorionizationtrails.ThisworkwassupportedinpartbyagrantfromtheKeyProgramsoftheChineseAcademyofSciencesduringthe11thFive-YearPlanPeriod,theNationalNaturalScienceFoundationofChinaunderGrantNo.60672129.Asakindofburstcommunication,MBChassuchcharacteristicsasanti-interference,lowprobabilityofinterception,longrangeforonehop.However,MBCcanbeusedonlywhenmeteorappearsintheirradiationareaofantenna.Thedurationofmeteorbursttrailsisveryshortabout300~500ms,consequently,themainproblemistoimprovethethroughput.Tomitigatethemulti-pathinterferenceinmeteorcommunication,fullduplexMBCsystembasedonOFDMispresented,whichcanimprovetheefficiencyofthetransmission.Inaddition,duetothefastfadingpropertyofmeteorbursttrails,anadaptivevariablerateschemeisproposed.ThenadigitalintegratedwithanalogAGCschemebasedonpowerdetectioninOFDMsignalsisputforwardtoreducethethresholdlevelofsystemandimprovetheutilizationofthechannel.Finally,theefficiencyofthesetechnologiesisdemonstratedbythetestresultsoftransmissionexperimentsinlaboratoryandfield.Keywords:MBCOFDMFullduplexAGCAdaptivevariablerate目录第一章概述..................................................................................................................11.1引言..................................................................................................................11.2流星余迹的通信机制及特点..........................................................................11.3流星余迹通信的发展历史和现状..................................................................21.4本文所做的工作及内容安排..........................................................................5第二章流星余迹通信的信道及传输特性..................................................................72.1流星的形成和分布..........................................................................................72.1.1流星的形成...............................................................................................72.1.2流星余迹的分类.......................................................................................72.1.3流星余迹的分布.....................................................................................102.2流星余迹信道的数学模型............................................................................122.2.1欠密类余迹的数学模型........