中压直流线OFDM载波通信技术的研究

硕士学位论文中压直流线OFDM载波通信技术的研究RESEARCHOFOFDMTECHNOLOGYINMEDIUMVOLTAGEDCPOWERLINECOMMUNICATION于皓杰哈尔滨工业大学2012年7月国内图书分类号：TM464学校代码：10213国际图书分类号：621.3密级：公开工学硕士学位论文中压直流线OFDM载波通信技术的研究硕士研究生：于皓杰导师：李浩昱教授申请学位：工学硕士学科：电力电子与电力传动所在单位：电气工程系答辩日期：2012年7月授予学位单位：哈尔滨工业大学ClassifiedIndex:TM464U.D.C:621.3DissertationfortheMasterDegreeofEngineeringRESEARCHOFOFDMTECHNOLOGYINMEDIUMVOLTAGEDCPOWERLINECOMMUNICATIONCandidate:YuHaojieSupervisor:Prof.LiHaoyuAcademicDegreeAppliedfor:MasterofEngineeringSpecialty:PowerElectronicsandPowerDrivesAffiliation:Dept.ofElectricalEngineeringDateofDefence:July,2012Degree-Conferring-Institution:HarbinInstituteofTechnology哈尔滨工业大学工学硕士学位论文I摘要中压直流电力线载波通信在油田测井数据传输中发挥着重要的作用。在生产测井领域，一般用直流单芯电缆对井下测井仪器进行供电，并同时实现地面处理设备与井下仪器之间的数据传输。测井技术的进步使得目前的测井数据量越来越大，对数据传输系统的要求越来越高，由于井下环境的特殊性，对测井电缆传输的准确性、实时性的要求很高，因此，为了提高数据传输速率和质量，开发高速可靠的电缆传输技术是非常必要的。在电力线通信领域，近年来正交频分复用(OFDM)因其出色的频带利用率和抗干扰能力，引起了人们广泛的关注，其应用领域也从无线通信扩展到有线通信中。本文首先对国内外电力线通信现状进行简要的分析，进而针对油田测井数据传输，分析了单芯电缆的传输特性，然后通过对传输过程中常用的几种编码调制技术与差错控制技术进行分析和对比，最终确定将具有高频带利用率和良好的抗干扰能力的OFDM技术作为本设计中的通信技术。结合差错控制编码，制定了基于OFDM调制技术的直流单芯电缆传输系统。然后，介绍了OFDM技术的基本原理和系统实现框架，根据单芯直流电缆通信特点，对OFDM技术进行改进和参数设计。参数确定后，以Altera公司的FPGA芯片为基础，以Modelsim作为仿真软件，对OFDM通信系统中的各个模块进行了设计和仿真，进而对调制器和解调器分别进行了整体的设计和仿真，并根据仿真结果验证设计的正确性。最后根据系统要求的通信速率，在FPGA开发板的基础上设计D/A、A/D硬件电路，把程序下载到硬件电路中，经过调试，得到完整的OFDM模拟信号。关键词：直流；单芯电缆；OFDM；FPGA哈尔滨工业大学工学硕士学位论文IIAbstractMediumvoltageDCpowerlinecommunicationplaysanimportantroleinoilwellloggingdatatransmission.Inthefieldofproductionlogging,generallyusingDCsingle-corecabletoprovidepowersupplyforundergroundloggingapparatus,meanwhile,toachievedatatransmissionbetweenthegroundhandlingequipmentsanddownholetools.Advancesinloggingtechnologymaketheamountofloggingdataincreasingfast,inaddition,becauseoftheparticularityoftheundergroundenvironment,itisrequiredthatthedatatransmissionofloggingcablemustbehigh-accurayandreal-time.Therefore,thedevelopmentofhigh-speedandreliablecabletransmissiontechnologyisnecessary.Inrecentyears,Orthogonalfrequencydivisionmultiplexing(OFDM)hasattractedpeople’sattentioninpowerlinecommunicationfield.BecauseOFDMhasexcellentbandwidthefficiencyandanti-jammingcapability,itsapplicationhasextendedtowiredcommunicationfromthewierlesscommunication.Thedissertationfirsttakesabriefanalysisofoverseasanddomesticresearchstatusofpowerlinecommunication.Andthenfortheoidfieldloggingdatatransmission,analysesthetransmissioncharacteristicsofsingle-corecable.Afterthat,throughanalysingandcomparingsomekindsofcommonmodulationandcodingtechnologiesanderrorcontroltechniquesusedincabletransmission,wedrawaconclusionthatusingOFDMasthecommunicationscheme,whichiswithhighbandefficiencyandgoodanti-interferenceability.Afteraseriesofanalyzes,wecomeupwithaDCsingle-corecabletransmissionsystemsbasedonOFDMtechnologycombinedwitherrorcontrolcoding.Then,weintroducethebasicprinciplesandimplementationframeworkofOFDM.InaccordancewiththeDCsingle-corecablecommunicationcharacteristics,improvesOFDManddesignesOFDMparametersusedinthisdissertation.Afterthat,basedonAlteraFPGAchipandModelsim,wegivethedesignandsimulationofvariousmodulesinOFDMsystem.Andthen,wetaketheoveralldesignandsimulationofmodulatorandemodulatorrespectivelyandverifythefeasibilityofthedesignaccordingtothesimulationresult.Finally,accodingtotherequiredcommunicationrate,givesthedesignofD/AandA/Dhardwarecircuits,thendownloadstheprogramtothehardwarecircuit,afterdebugging,wecanobtaintheOFDManalogsignal.Keywords:DC,single-corecable,OFDM,FPGA哈尔滨工业大学工学硕士学位论文III目录摘要............................................................................................................................IAbstract.........................................................................................................................II第1章绪论..............................................................................................................11.1课题研究目的和意义........................................................................................11.2国内外研究现状与分析....................................................................................21.2.1电力线通信概述.........................................................................................21.2.2测井数据传输现状.....................................................................................31.2.3OFDM发展现状.........................................................................................51.2.4可编程逻辑器件.........................................................................................51.3存在的问题和发展趋势....................................................................................61.4本文主要研究内容............................................................................................6第2章单芯电缆传输分析..........................................................................................82.1单芯电缆传输特性分析....................................................................................82.1.1单芯电缆电路模型.....................................................................................82.1.2单芯电缆频率特性分析..............................................................