Joint wireless communication and radar sensing system1.docx
- 文档编号:5338688
- 上传时间:2022-12-15
- 格式:DOCX
- 页数:12
- 大小:28.32KB
Joint wireless communication and radar sensing system1.docx
《Joint wireless communication and radar sensing system1.docx》由会员分享,可在线阅读,更多相关《Joint wireless communication and radar sensing system1.docx(12页珍藏版)》请在冰豆网上搜索。
Jointwirelesscommunicationandradarsensingsystem1
Jointwirelesscommunicationandradarsensingsystems–stateoftheartandfutureprospects
LiangHan,KeWu
Poly-GramesResearchCenter,CenterforRadiofrequencyElectronicsResearchofQuebec(CREER),DepartmentofElectricalEngineering,EcolePolytechnique,UniversityofMontreal,Montreal,Quebec,CanadaH3T1J4E-mail:
liang.han@polymtl.ca
Abstract:
Thehistoricaldevelopmentandcurrentstate-of-the-artofvariousjointwirelesscommunicationandradarsensingsystemsarereviewedanddiscussedinthisstudy.Differentkindsofsystemsarecategorisedaccordingtotheirmodulationwaveformsandduplexschemes.Prosandconsofeachcategoryarehighlighted.Toshowcasethecurrentresearchadvances,severaldemonstrationsystemsareintroducedwithemphasisonproposedresearchcontributionsinthisemergingarea,andtheirperformancesarecomparedwithrespecttobothcommunicationandradarmodes.Also,anumberofchallengesareidentifiedforthenearfuturesystemdevelopmentsandapplications.
1Introduction
Theinventionofradiousheredthehistoryofmankindintoanewera.Amongvarioustypesofradioapplicationsknowntodate,themostubiquitousandprominenttwoofthemarewirelesscommunicationandradarsensing.Sincetheverybeginning,thesetwosortsofsystemshavebeendesignedanddevelopedinaquitedifferentmanner,eventhoughbothmakeuseofradiofrequencytransceiverfunctionalblocks.Ofcourse,theyhavegenerallybeenindependentlyandseparatelystudiedanddevelopedfromeachotherinmostscenariosexceptforsomeprimitiveapplicationexamplesofsystemfusionbetweenthemsuchastheso-calledsecondarysurveillanceradarsystemortheidentificationfriendorfoe(IFF)system[1].Althoughinformationexchangeisenabledinsuchkindofradarsystems,theresponderisingeneralnotabletotransmitdatatotheinterrogatorautonomously.Thereforedatafusionschemesbasedonthiskindofsystemoperation,thatis,radar-embeddedcommunications[2]andUWBRFID[3],willnotbefurtherdiscussedinthispaperbecausesuchsystemsdonotpresenta‘truly’blendedtransceiverarchitecturethatsimultaneouslypossessescommunicationandradarfunctions.
Ifsuccessfullyimplemented,thesystemfusionofwirelesscommunicationandradarsensingwoulddefinitelybringupmanybenefitsincludingarchitectureunificationandsimplification,functionalreconfigurationandfusionandespeciallyefficiencyenhancementandcostreduction.Naturally,thefusionoftwosystemsthroughonesingletransceiverallowsthereal-timeinterplayand‘dialogue’betweentwodifferentfunctions.AnearlyexampleofintegratedradarandcommunicationsubsystemcanbetracedbacktotheNASASpaceShuttleOrbiter[4].Recently,therehasbeenamultitudeofemergingneedsforintegratingwirelesscommunicationandradarsensingsystems.Theintelligenttransportationsystems[5],forexample,requireintelligentvehiclestohavethecapabilityofautonomouslysensingthedrivingenvironmentandcooperativelyexchanginginformationdatasuchasvelocityandbrakingbetweenvehiclesandalsoroad,trafficandweatherconditionsaswellasentertainmentcontentamongvehiclesandbeacons.Anotherexampleisthewirelesssensornetworks(WSN)[6]forpositioningandmonitoringpurposes,inwhicheachnodedetectstargetsandsharesitsinformationwithothernodesthroughwirelesscommunicationlinks,whichshouldbedesirablypartoftheWSNsystem.Furthermore,itshouldbementionedthatmultifunctionalin-situsystemswithactiveprotectionradar,widebandcommunicationsandcombatidentificationarealsohighlydemandedformodernmilitaryapplications[7].
Theunprecedentedsystemfusionhasgenerallypresentedmanystringentdesignrequirementssuchaslow-cost,simpleimplementation,flexiblefunctionalreconfigurationandhigh-powerefficiencyaswellasfastresponse.Thisisbecausethesystemfusionorintegrationshouldbemuchmoreadvantageousthanitspuremechanicallyassembledcounterpartoftwoseparatesystemarchitectures.Inthepasthalf-decade,anumberofsystemconceptswithrespecttowaveformdesignandtransceiverdevelopmenthavebeenproposedtointegratebothwirelesscommunicationandradarsensingfunctionswithinasingletransceiversystem.Thispaperbrieflyreviewsandsummarisesthestate-of-the-artsystems,describesanddiscussessomedemonstrationsystems,andpointsoutseveralchallengesforfuturesystemdevelopments.
2Waveformdesign
Differentunderlyingoperationprinciplesofwirelesscommunicationandradarsensingsystemssuggestdifferentrequirementswithregardtocertainsystemandtransceiverdesignconsiderations,suchasduplexmode,modulationschemeandbandwidthaswellassignalprocessingalgorithms.Forinstance,frequencydivisionduplexmodecommonlyusedinwirelesscommunicationisnotsuitableforradarapplicationssincethespectraoftransmittedandreceivedradarsignalsarealmostco-locatedinthesamefrequencychannel.Inmostcases,thedesignrequirementsforcommunicationandradarfunctionsmaybeinconflict,whichposeagreatchallengeinthedevelopmentofsuchsystemarchitecturefusions.Withrapidprogressofdigitalcircuits,therehasbeenatrendtosimplifythedesignofradio-frequency(RF)front-endcircuitsbyimplementingmostofthesystemfunctionsbaseduponsoftware-reconfigurablesignalprocessingalgorithms.Thesesoftware-definedradioplatformsprovideuswithagoodopportunitytoachievejointcommunicationandradaroperationswithinthesameRFfront-endcircuit.
Table1summarisestheprosandconsoftypicalcommunication–radarfusionschemesthathaverecentlybeenproposedandstudiedin[8–24].Thejointwaveformschemecanbefurthercategorisedintosingle-carrierandmulti-carriersystems.Inthesingle-carriersystems,thefrequency-domainschemeisfoundmuchlesspopularthanitscode-domain(spreadspectrum)counterpartsbecauseofthemutualorcross-channelinterferencecausedbythespectrumoverlapping[8].Thespreadspectrumtechniquewasfirstlyimplementedinaboomerangtransmissionsystemforvehicularcommunicationandrangingapplications[9].Essentially,theproposedsystemissimilartoanIFFsystemexceptthatitadoptsthedirect-sequencespreadspectrum(DSSS)techniquetoimprovethesystemperformance.Followingthatdevelopment,thespreadspectrumtechniquehaswidelybeenexploitedforfusingcommunicationandradarfunctions,suchasDSSS[9–13],THSS[14]andCSS[15].Thecode-domainschemesallowforsecurecommunicationandhigh-resolutionrangingattheexpenseofutilisingexcessivespectrumresourcesfordatacommunication.Moreover,differentuserscansharethesamefrequencybandsimultaneouslybyusingdifferentspreadingcodes,whichisverybeneficialformultiuserapplicationscenarios.RegardingtheradarrangingandDopplerestimationbasedonthespreadspectrumtechnique,therearetwomaindrawbacks.Oneisthatthepeak-to-sideloberatioislimitedbytheimperfectauto-correlationcharacteristicsofthepseudorandomcodes,anditisalsoimpactedbythespreadingfactorandtheDopplershift.TheotheristhatforDopplerprocessing,thespreadspectrumtechniquerequiresahugeamountofcomputations.Ingeneral,theconcernofusingaspreadspectrumtechniqueisrelatedtoitshighcomplexityandcostandlowefficiencyintermsofsystemimplementation.
Multi-carrier,especiallytheorthogonalfrequency-divisionmultiplexing(OFDM)technique,whichhaswidelybeenusedinwirelesscommunications,wasalsointroducedinthedesignofradarwaveform[25].TheuseofOFDMradarwaveformswasdemonstratedinmultiple-inputandmultipleoutput(MIMO)radarsystems[16]andradarnetworks[26,27]aswellassyntheticapertureradar(SAR)systems[17,28–30].OneattractivefeatureoftheOFDMradarsignalsisthatthereisnorange–DopplercouplingissueandthereforeindependentrangeandDopplerprocessingbecomespossible[31,32].Inthepastfewyears,differentsignalprocessingtechniqueshavebeenproposedandimplemented.Inthebeginning,matchedfilterswereusedtoperformrangeandDopplerestimationin[18,33–37].However,correlation-basedprocessingmethodstillsuffersfromsuchproblemsaslowdynamicrange(orpeak-to-sideloberatio)andambiguities.Inordertoincreasethedynamicrangeandpreservethetransmittedcommunicationdata,anovel‘modulationsymboldomain’OFDMprocessingalgorithmwasproposed[38–41]andvalidatedthroughexperimentalsystemprototypes[19,42].Althoughpreservingtheresolutionandtheprocessinggainofthecorrelation-basedprocessingmethod,thisadvancedjointrangeandDopplerestimationalgorithmfortheOFDM-basedjointwaveformhasmuchhigherdynamicrangethanthesingle-carrierspreadspectrumapproachbymanyordersofmagnitude,especiallyforhighSNRlevels.Moreover,theDopplerfrequency(ortargetrelativevelocity)canbeeasilyestimatedindependentlyfromthetargetrange.Acomprehensivereviewoftheproposedsignalprocessingtechniqueandrelatedsystemdemonstrationcanbefoundin[43].Thistechniquehasbeenrecentlyextendedtotackleamultipathandmultiuserscenarioin[44].AlthoughtheOFDMtechniqueshavepresentedanumberofadvantageslistedinTable1,thehighimplementationcostofOFDMsystemsbecauseofthecomplexsignalprocessingandhighpeak-to-averagepowerratioofOFDMsignalsstillimpedetheirwidespreadapplications.
Almostinparallelwiththejointwaveformscheme,thetime-domainduplexschemehasalsostimulatedresearchinterestbecauseofitshighspectralefficiencyandeasysystemimplementationaswellaslowcost[20–24].Inthetime-domainplatforms,comm
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- Joint wireless communication and radar sensing system1
链接地址:https://www.bdocx.com/doc/5338688.html