目錄：IntroductiontoWirelessCommunicationsRadioPropagationNarrowbandChannelWidebandandDirectionalChannelDigitalModulationandDemodulationChannelCoding第1題Wirelesscommunicationisacommunicationmethodthatusesthecharacteristicsofelectromagneticwavestopropagateinspacetoexchange()AenergyBinformationCmatterDbothmatterandenergy第2題Amongthefollowingelectromagneticwaves,whichhasthelongestwavelength(i.e.thelowestfrequency)?AMicrowaveBInfraredrayCVisiblelightDUltrashortwave第3題Thephysicistwhofirstconfirmedthatelectromagneticenergycanspreadacrossspaceviaexperimentsis().AMichaelFaradayBIsaacNewtonCHeinrichRudolfHertzDJamesClerkMaxwell第4題Whichcommunicationssystemisnotbelongtothewirelesscommunicationssystems?ASatellitecommunicationBOpticalfibercommunicationCCellularmobilecommunicationDBluetoothcommunication第5題Whichdoesnotconformtothecharacteristicsofthefirstgenerationcellularmobilecommunications(1G)?AAnalogcommunicationsBOnlycarryvoiceservicesCLowcostDBulkyterminals第6題Whichstandarddoesnotbelongtothethirdgenerationmobilecommunications(3G)?AGSMBWCDMACTD-SCDMADCDMA2000第7題5Gsystemapplicationscenariosinclude().Aenhancedmobilebroadbandcommunications(eMBB)Bmassivemachine-typecommunications(mMTC)Cultra-reliablelowlatencycommunications(uRLLC)Dwideareacoveragecommunications正確答案：ABC第8題Whoaretheinventorsoftheradiotelegraph?AJamesClerkMaxwellBHeinrichRudolfHertzCAlexanderStepanovichPopovDGuglielmoMarconi正確答案：CD第9題Whichisnotinthemillimeterwaveband?A28GHzB39GHzC73GHzD2.4GHz第10題Whichcharacteristicdoesnotconformtothebroadcast/televisioncommunicationssystem?AUnidirectionaltransmissionBWidecoverageCLowcostDAbletocallandbecalled第11題Whicharethefeaturesofsatellitecommunications?AWidecoverageBThecostofbuildingastationhasnothingtodowiththecommunicationdistanceandthenaturalenvironmentofthemobilestationCGoodresistanceDLowtransmissionlatency正確答案：ABC第12題Whicharethefeaturesofwirelesslocalareanetwork(WLAN)?AHightransmissionrateBMainlyuselicensedfrequencybandsCGoodcompatibilityDMiniaturizationandlowcost正確答案：ACD第13題Whichareshort-rangewirelesscommunicationsystems?ABluetoothBRFIDCUWBDNFC正確答案：ABCD第14題WhichstatementsaboutLTEarecorrect?AIncludingLTEFDDandTD-LTEtwostandardsBHightransmissionrateCFlexiblesystemdeploymentDGuaranteedqualityofservice正確答案：ABCD第15題In2019,()cellularmobilecommunicationssystemisofficiallyputintocommercialuseinChina.A2GB3GC4GD5G第1題Whichofthefollowingisusedtodescribetherelationshipbetweentransmitpowerandreceivedpowerinfree-spacepropagationofradiowaves?AFriis’LawBHuygensprincipleCSnell’sLawDShannonTheory第2題WhatarethescoperequirementsforFriis’law?ATransceiverdistanceismuchsmallerthanwavelength.BTransceiverdistanceismuchgreaterthanwavelength.CTransceiverdistanceislessthanRayleighdistance.DTransceiverdistanceisgreaterthanRayleighdistance.正確答案：CD第3題Fordirectpropagation,wherethetransceiverisatacertaindistance,therelationshipbetweenpathlossandcarrierfrequencyis_____.AAsthefrequencyincreases,thepathlossbecomeslarger.BAsthefrequencyincreases,thepathlossbecomessmaller.CPathlossisindependentoffrequency.DAsthefrequencyincreases,thepathlosschangesrandomly.第4題Thefrequencyofasatellitecommunicationssystemis40GHz,thedistancefromthegroundreceiveris20,000km,andthepathlossis_____.A121.4dBB210.5dBC270.5dBD330.5dB第5題Ingeneral,thepenetrationlossofthetraincoachis()thepenetrationlossofdensefoliage.AequaltoBsmallerthanClargerthanDnotabletocomparewith第6題TheamplitudeofGaussianwhitenoisefollows().AuniformdistributionBnormaldistributionCGammadistributionDRiciandistribution第7題Inordertoreducethecompositenoisefigureoftheentirereceiver,thereceiverfrontendgenerallyuses().AhighgainamplifierBlownoiseamplifierCfrequencyMixerDattenuator第8題Theelectromagneticwavesemittedbythetransmitterareirradiatedtoobjectssmallerthanthecarrierwavelength(suchasstreetlights,leaves,trafficsigns,etc.),andthephenomenonofreflectingmultipleweakelectromagneticwavesiscalled().AdirectwaveBtransmissionCdiffractionDscattering第9題Ingeneral,thehigherthefrequency,thesmallerthediffractionloss.第10題Undernormalroomtemperature(290K),thebasicthermalnoisepowerspectraldensityisabout-174dBm/Hz第11題Infreespacepropagation,thepathlossisproportionaltothesquareofthetransceiverdistance.第12題Whenthetransceiverdistanceisdetermined,comparedwiththefreespacepropagationscenario,thepathlosswillbereducedafterconsideringtheeffectofgroundreflectedwaves.第13題Antennagainindicatesthepoweramplificationofthesignalafterpassingthroughtheantenna.第14題Whenperforminglinkbudgeting,increasingthefadingmargincanreducetheprobabilityofsystemoutages.第15題Themechanismofradiowavepropagationincludes().AdirectwaveBreflectionCdiffractionDscattering正確答案：ABCD第16題Ifthetransmitter'stransmitpoweris2Wattsandthetransmitantennagainis7dB,whatistheeffectiveomnidirectionalradiatedpower(EIRP)indBm?A9B14C10D40Exercise13第1題Shadowfadinggenerallyfollows().AnormaldistributionBuniformdistributionCexponentialdistributionDlog-normaldistribution第2題Theamplitudeofsmall-scalefadingwithoutdominantcomponentsfollows().AnormaldistributionBuniformdistributionCRayleighdistributionDlog-normaldistribution第3題Thevarianceofshadowfadinginurbanenvironmentisgenerally()thevarianceofshadowfadinginruralenvironment.AequaltoBsmallerthanCgreaterthanDNotcertain第4題Theamplitudeofsmall-scalefadingwithdominantcomponentsfollows().ARiciandistributionBexponentialdistributionCRayleighdistributionDlog-normaldistribution第5題TheRicianfactorisdefinedastheratioofscatteredcomponentenergytodirectcomponentenergy.第6題IntheRayleighchannel,toensurethattheoutageprobabilityis1%,thefadingmarginshouldbe().A10dBB20dBC23dBD30dB第7題Whenasystemworksat1900MHzandthemovingspeedis40km/h,themaximumDopplerfrequencyshiftis().A47.5HzB70.4HzC253.3HzD76kHz第8題Whichofthefollowingstatementsaboutchannelfadingiscorrect?AThelargertheRicianfactor,themoresignificantthechannelfading.BThegreatertheDopplerfrequencyshift,theslowerthechannelfading.CThemoreopenthesurroundingenvironmentofthetransmitterandreceiver,themoresignificantthechannelfading.DThemoresignificantthechannelfading,thegreaterthefadingmarginrequired.第9題Assumingthatthelarge-scalefadingfollowsalog-normaldistributionwithastandarddeviationof5dB,whenthelarge-scalefadingmarginissetto10dB,withoutconsideringthesmall-scalefading,theprobabilityofoutageis().A0.015B0.022C0.032D0.15第10題Thephaseofsmall-scalefadingwithoutdominantcomponentsfollows().AGaussiandistributionBuniformdistributionCRayleighdistributionDlog-normaldistribution第11題Large-scalefading,alsoknownasshadowfading,ismainlycausedbyterrainundulationandlarge-scaleobjectocclusion.第12題TheRayleighchannelcanberegardedasaspecialcasewhentheRicianfactortendstoinfinity.第13題Whenthereceivermovesinthedirectionoftheincomingwave,theDopplershiftispositive.第14題Ingeneral,thegreatertheDopplerfrequencyshift,thegreatertheaveragefadingdurationofthechannel.Exercise4第1題Theimpactsofmultipathpropagationonbroadbandsignaltransmissioninclude().Ainter-symbolinterferenceBerrorfloorCfrequencyselectivefadingDenergyattenuation正確答案：ABC第2題Techniquesagainstmultipathpropagationinclude().AequalizationBdiversityCOFDMDMIMO正確答案：ABCD第3題WhichstatementabouttheassumptionofWideSenseStationaryUncorrelatedScattering(WSSUS)isincorrect?AChannelstatisticsvarywithtime.BFadingexperiencedbysignalswithdifferentDopplerfrequencyshiftsisuncorrelated.CFadingexperiencedbysignalswithdifferentdelaysisuncorrelated.DTransferfunctionisstableinthefrequencydomain.第4題Generally,thedelayspreadintheurbanenvironmentis()thatinthesuburbanenvironment.AgreaterthanBsmallerthanCequaltoDnotcertain第5題Asystemworksat1.9GHzandthemobilestationmovesataspeedof100km/h.AssumingDoppleristheClassicspectrum,thechannelcoherencetimeis().A0.25msB1.3msC5.9msD10ms第6題Whenthesignalbandwidthisgreaterthanthechannelcoherencebandwidth,thesignalexperiences().AfrequencyselectivefadingBflatfadingCfastfadingDslowfading第7題Whenthesymboldurationisgreaterthanthechannelcoherencetime,thesignalexperiences().AflatfadingBfrequencyselectivefadingCslowfadingDfastfading第8題Inthefrequencyselectivefadingchannel,thefadingofeachfrequencycomponentisalmostthesame,thefadingconditionisindependentofthefrequency,andthereceivedsignalwaveformisnotdistorted.第9題Thechannel'sstationarycharacteristicandtime-varyingcharacteristicarethesameconcept.第10題Whichoneisthedirectionalchannelmodel?AWINNERmodelBRayleighmodelCRicemodelDCOST207modelExercise5第1題Theguidelinestobefollowedwhenchoosingamodulationschemeinclude().AhighbandwidthefficiencyBlowbandwidthefficiencyCsensitivetonoiseDnotsensitivetonoise正確答案：AD第2題UsingBPSKmodulation,theraisedcosineroll-offcoefficienta=0.2,thenthespectrumutilizationofthesignalis().A1bit/s/HzB1.67bit/s/HzC0.5bit/s/HzD0.83bit/s/Hz第3題Themaximumphasechangeofconstellationpointsintheπ/4-DQPSKmodulationis?Aπ/4Bπ/2C3π/4Dπ第4題OneQPSKsymbolcarries()bits.A1B2C3D4第5題ForMSKmodulation,f1=1200Hz,f2=600Hz,themaximumbitrateis().A300bits/sB600bits/sC1200bits/sD2400bits/s第6題WhatisthenumericalrelationshipbetweenthemainlobebandwidthofthefrequencybandmodulatedbyMSKandGMSKandthebitrateRb?A0.75RbBRbC1.5RbD2Rb第7題InAWGNchannel,whatistherequiredsignal-to-noiseratiotogetthebiterrorrateof10^-5inQPSKdemodulation.A6dBB6.9dBC9dBD9.6dB第8題UnderAWGNchannelandwiththesamesignal-to-noiseratio,theerrorperformanceofBPSKcoherentdemodulationis()theerrorperformanceofBPSKdifferentialdemodulation.AsuperiortoBinferiortoCthesamewithDnotcertain第9題InRayleighfadingchannel,thebiterrorrateofBPSKcoherentdemodulation()withtheaveragesignal-to-noiseratio.AproportionallyincreasesBinverselydecreasesCexponentiallydecreasesDlogarithmicallydecreases第10題Underthedelayandfrequencydispersionchannel,whichparametersarerelatedtotheerrorfloorofthebiterrorrate?ARootmeansquaredelayspreadofthechannelBMaximumDopplershiftCSymbolrateDAveragesignal-to-noiseratio正確答案：ABCExercise6第1題AbinarylinearblockcodewithHammingdistance5cancorrect()biterrorsatmost.A6B3C2D1正確答案：C第2題CyclicRedundancyCheck(CRC)codeiswidelyusedin().AerrorcorrectionBerrorcorrection