外文翻譯通信工程英文的畢業(yè)設(shè)計論文

編號:,輟我/甯孑科徐大珍GUILINUMIVERSITYOFELECTHONtCTECHNOLOGY畢業(yè)設(shè)計〔論文〕外文譯

〔譯文〕學(xué)院：信息與通信學(xué)院專業(yè)：通信工程學(xué)生姓名：學(xué)號：指導(dǎo)教師單位:信息與通信學(xué)院姓名：職稱：2022年2月9日RadionetworkplanningprocessandmethodsforWCDMAAbstractThispaperdescribesthesystemdimensioningandtheradionetworkplanningmethodologyforathirdgenerationWCDMAsystem.Theapplicabilityofeachmethodisdemonstratedusingexamplesoflikelysystemscenarios.Thechallengesofmodelingthemultiserviceenvironmentaredescribedandtheimplicationstothesystemperformancesimulationsareintroduced.Keywords:Telecommunicationnetworkplanning,Mobileradio-communication,Codedivisionmultipleaccess,Widebandtransmission,Multipleservicenetwork,Dimensioning,Simulator,Staticmodel,Dynamicmodel,Cellularnetwork.Resume⑺ContentsIntroductionInitialplanning,systemdimensioningDetailedplanningprocessExampledimensioningcaseandverificationofdimensioningwithstaticsimulationsComparisonofastatictoadynamicnetworksimulatorVI.ConclusionINTRODUCTIONAsthelaunchofthirdgenerationtechnologyapproaches,operatorsareformingstrategiesforthedeploymentoftheirnetworks.Thesestrategiesmustbesupportedbyrealisticbusinessplansbothintermsoffutureservicedemandestimatesandtherequirementforinvestmentinnetworkinfrastructure.Evaluatingtherequirementfornetworkinfrastructurecanbeachievedusingsystemdimensioningtoolscapableofassessingboththeradioaccessandthecorenetworkcomponents.Havingfoundanattractivebusinessopportunity,systemdeploymentmustbeprecededbycarefulnetworkplanning.Thenetworkplanningtoolmustbecapableofaccuratelymodelingthesystembehaviourwhenloadedwiththeexpectedtrafficprofile.Thethirdgenerationcellularsystemswillofferserviceswellbeyondthecapabilitiesoftoday'snetworks.Thetrafficprofile,aswellastheradioaccesstechnologyitselfformthetwomostsignificantchallengeswhendimensioningandplanningaWCDMAbasedthirdgenerationsystem.Thetrafficprofiledescribesthemixtureofservicesbeingusedbythepopulationofusers.Therearealsospecificsystemfunctionalitieswhichmustbemodelledincludingfastpowercontrolandsofthandover.InordertoaccuratelypredicttheradiocoveragethesystemeaturesassociatedwithWCDMAmustbetakenintoaccountinthenetworkmodelingprocess.Especiallythechannelcharacterization,andinterferencecontrolmechanismsinthecaseofanyCDMAsystemmustbeconsidered.InWCDMAnetworkmultipleservicesco-exist.Differentservices(voice,data)havedifferentprocessinggains,Eb/N0performanceandthusdifferentreceiverSNRrequirements.InadditiontothosetheWCDMAcoveragedependsontheloadcharacterization,handoverparameterization,andpowercontroleffects.Incurrentsecondgenerationsystems'coverageplanningprocessesthebasestationsensitivityisconstantandthecoveragethresholdisthesameforeachbasestation.InthecaseofWCDMAthecoveragethresholdisdependentonthenumberofusersandusedbitratesinallcells,thusitiscellandservicespecific.TheWCDMAplanningprocesscanbedividedintothreephases:initialplanning(dimensioning),detailedradionetworkplanningandnetworkoperationandoptimization.Eachofthesephasesrequiresadditionalsupportfunctionslikepropagationmeasurements,KeyPerformanceIndicatordefinitionsetc.Inacellularsystemwherealltheairinterfaceconnectionsoperateonthesamecarrierthenumberofsimultaneoususersisdirectlyinfluencingonthereceivers'noisefloors.Therefore,inthecaseofVMTStheplanningphasescannotbeseparatedintocoverageandcapacityplanning.Inthecaseofthepostsecond-generationsystemsdataservicesstarttoplayanimportantrole.Thevarietyofservicesrequiresthewholeplanningprocesstoovercomeasetofmodifications.Oneofthemodificationsisrelatedtothequalityofservice(QoS)requirements.Sofarithasbeenadequatetospecifythespeechcoverageandblockingprobabilityonly.Alsomoreandmoreonehastoconsidertheindoorandin-carcoverageprobabilities.InthecaseofUMTStheproblemisslightlymoremultidimensional.ForeachservicetheQoStargetshavetobesetandnaturallyalsomet.Inpracticethismeansthatthetightestrequirementshalldeterminethesitedensity.InadditiontothecoverageprobabilitythepacketdataQoScriteriaarerelatedtotheacceptabledelaysandthroughput.Estimationofthedelaysintheplanningphaserequiresgoodknowledgeoftheuserbehaviourandunderstandinginthefunctionsofpacketscheduler.Commonfeaturesbetweensecondandthirdgenerationcoveragepredictionalsoexist.Inallthesystemsbothofthelinkshavetobeanalyzed.Incurrentsystemsthelinkstendtobeinbalancewhereasinthecaseofthirdgenerationoneofthelinkscanbehigherloadedthantheother,andthuseitheroneofthelinkscouldbelimitingthecellcapacityorcoverage.Thepropagationcalculationisbasicallythesameforallstandards,withtheexceptionthatdifferentpropagationmodelscouldbeused.Anothercommonfeatureistheinterferenceanalysis.InthecaseofWCDMAthisisneededfortheloadingandsensitivityanalysis,inthecaseofTDMA/FDMAitisessentialforfrequencyallocation.InordertofullyutilizetheWCDMAcapabilities,athoroughunderstandingoftheWCDMAairinterfaceisneededfromthephysicallayertothenetworkmodeling,planningandperformanceoptimization.Inthispaperthepre-operationalphaseoftheWCDMAplanningprocess,asdepictedinFigure1indetail,isdiscussed.SectionIIisconcentratingontheinitialplanningissues.TheWCDMAlinkbudgetisintroducedanditisdemonstratedhowdifferentservicesandtheirQoSrequirementsimpactonthesitedensityestimate.InSectionIIIastaticradionetworksimulatorisintroduced.ThemethodologyrequiredinthecoverageandcapacityestimationforWCDMAisdescribedforbothuplinkanddownlink.TopicofSectionIVistodemonstratetheaccuracyofdimensioning:anexampleareaisdimensionedandtheaveragesitedistanceisdetermined.Thedimensioningresultiscomparedwiththeoutcomeofastaticnetworksimulation.InSectionVtheanalysismethodsofthestaticsimulatorareverified.Theverificationwasperformedwithadynamicsystemsimulator.ThepaperisconcludedinSectionVI.INITIALPLANNING,SYSTEMDIMENSIONINGInitialplanning(i.e.systemdimensioning)providesthefirstandmostrapidevaluationofthenetworkelementcountaswellastheassociatedcapacityofthoseelements.Thisincludesboththeradioaccessnetworkaswellasthecorenetwork.Thispaperfocusesupontheradioaccesspartsolely.Thetargetoftheinitialplanningphaseistoestimatetherequiredsitedensityandsiteconfigurationsfortheareaofinterest.Initialplanningactivitiesincluderadiolinkbudget(RLB)andcoverageanalysis,capacityestimation,andfinally,estimationfortheamountofbasestationhardwareandsites,radionetworkcontrollers(RNC),equipmentatdifferentinterfaces,andcorenetworkelements.Theservicedistribution,trafficdensity,trafficgrowthestimatesandQoSrequirementsareessentialalreadyintheinitialplanningphase.Intheinitialplanningphasethequalityistakenintoaccountintermsofblockingandcoverageprobability.RLBcalculationisdoneforeachservice,andthetightestrequirementshalldeterminethemaximumallowedisotropicpathloss.A.WCDMAspecificitemsintheradiolinkbudgetInthissectiontheWCDMAuplinkanddownlinkbudgetsarediscussed.ToestimatethemaximumrangeofacellaRLBcalculationisneeded.IntheRLBtheantennagains,cablelosses,diversitygains,fadingmargins,diversitygainsetc.aretakenintoaccount.TheoutputoftheRLBcalculationisthemaximumallowedpropagationpathlosswhichinreturndeterminesthecellrangeandthustheamountofsitesneeded.ThereareafewWCDMAspecificitemsinthelinkbudgetifonecomparestothecurrentTDMAbasedradioaccesssystemlikeGSM.Theseincludeinterferencedegradationmargin,fastfadingmargin,transmitpowerincreaseandsofthandovergain.Theinterferencedegradationmarginisafunctionofthecellloading.Themoreloadingisallowedinthesystem,thelargerinterferencemarginisneededinuplink,andthesmalleristhecoveragearea.Theuplinkloadingcanbederivedasfollows,forsimplicitythederivationisperformedwithserviceactivityv=1.TofindouttherequireduplinktransmittedandreceivedsignalpowerforamobilestationMSkconnectedtoaparticularbasestationBSn,thebasicCDMAEb/N0equationisused.Theusual,slightlytheoretical,assumptionisthatIoth,theinterferencereceivedfromtheMSsconnectedtotheothercellsisdirectlyproportional(proportionalityconstanti)toIown,theinterferencereceivedfromtheMSsconnectedtothesameBSnasthedesiredMS.AssumethattheMSkusesbitrateRk,itsEb/N0requirementisPkandtheCDMAmodulationbandwidthisW.Thenthereceivedpowerofthek-thmobile,Pk,atthebasestationitisconnectedto,mustbeatleastsuchthat公式(1)k=l.....KwhereKnisthenumberofMSsconnectedtoBSn,N=NoW=NfkToWisthenoisepowerinthecaseofanemptycell,Nfisthereceivernoisefigure,kistheBoltzmannconstantandTOistheabsolutetemperature.Theinequalitiesin(1)areslightlyoptimisticbecauseitisassumedthatthereisnointerferencefromtheownsignal.Inrealitythisisnotexactlytrueinmultipathpropagationconditions.Equation(1)ishoweverstillchosentoavoidtakingmultipathinterferenceintoaccounttwice.I.e.,theEb/N0requirementsdeterminedfromlinklevelsimulationsarepresentedsothatN0meansonlynoiseandmultipathinterferenceisvisibleinhigherEb/N0requirementtoacertainBERperformance.Solvingtheinequalitiesasequalitiesmeanssolvingfortheminimumrequiredreceivedpower(sensitivity),Pk:公式⑵IftheEquationsin(2)aresummedoverthemobilestationsconnectedtoBSnthen公式公式(3)since/ow,=~Pk'Ifloadingisdefinedask公式(4)thisloadingdefinitioncanbeenhancedtoincludegainandserviceactivity,v:公式(5)In[12]theuplinkloadingisestimatedusingequation公式(6)wheremisthenumberofservicesused.ThedifferencebetweenEquations(5)and(6)areduetothefactthat(6)doesnotincludesectorisationgainandthatinthederivationstartingfromEquation(1)thedenominatorisIown-Pk+iIow+NratherthanIown+iIown+N,whichisonlythecasewhenPk<<Iown"Thedownlinkdimensioningisfollowingthesamelogicastheuplink.Foraselectedcellrangethetotalbasestationtransmitpoweroughttobeestimated.Inthisestimationthesofthandoverconnectionsmustbeincluded.Ifthepowerisexceededeitherthecellrangeoughttobelimited,ornumberofusersinacellhastobereduced.Fordownlinktheloading(刀DL)isestimatedbasedon公式(7)whereLPmiisthelinklossfromtheservingBSmtoMSi,LPniisthelinklossfromanotherBSn,toMSi,PiisthetransmitEb/N0requirementfortheMSi,includingtheSHOcombininggainandtheaveragepowerraisecausedbyfastpowercontrol,Nisthenumberofbasestations,Iisthenumberofconnectionsinasectorandaiistheorthogonalityfactordependingonmultipathconditions(==1:fullyorthogonal).公式：Theterm~"definestheiDL.n=l,n~:mLPniDirectoutputofthedownlinkRLBisthesinglelinkpowerrequiredbyauseratthecelledge.Thetotalbasestationpowerestimationmusttakeintoaccountmultiplecommunicationlinkswithaverage(LPmi)distancefromtheservingbasestation.Furthermore,themulticellenvironmentwithorthogonalitiesaishouldbeincludedinthemodeling.Moreonthedownlinkloadingandtransmitpowerestimationscanbefoundin[13].IntheRLBcalculationinuplinkdirectionthelimitingfactoristhemobilestationtransmitpower,indownlinkdirectionthelimitisthetotalbasestationtransmitpower.Whenbalancingtheuplinkanddownlinkserviceareasbothlinksmustbeconsidered.FastfadingmarginorpowercontrolheadroomisanotherCOMAspecificitemintheRLB.Somemarginisneededinthemobilestationtransmissionpowerformaintainingadequateclosedloopfastpowercontrolinunfortunatepropagationconditionslikethecelledge.ThisisapplicableespeciallyforpedestrianuserswheretheEb/N0tobemaintainedismoresensitivetotheclosedlooppowercontrol.Thepowercontrolheadroomhasbeenstudiedmorein[6]and[7].Anotherimpactofthefastpowercontrolisthetransmitpowerincrease.Inthecaseofaslowlymovingmobilestationthepowercontrolisabletofollowthefadingchannelandtheaveragetransmittedpowerincreases.Inowncellthisisneededtoprovideadequatequalityfortheconnectionanddoesnotcauseanyharm,sinceincreasedtransmitpoweriscompensatedbythefadingchannel.Forneighbouringcellshoweverthismeansadditionalinterference.Thetransmitpowerincrease(TxPowerlnc)isusedtoreducethereuseefficiencyaccordingtoEquation(9).InEquation(4)ishouldbereplacedwithtermTxPowerlncXiincasethemobilestationtransmitpowerincreaseissignificant.Softhandovergainisdiscussedalreadyin[3].Handovers-softorhard-providegainagainstshadowfadingbyreducingtherequiredfadingmargin.Duetothefactthattheslowfadingispartlyuncorrelatedbetweencells,andbymakinghandoversthemobilecanselectabettercommunicationlink.Furthermore,softhandover(macrodiversity)givesanadditionalgainagainstfastfadingbyreducingtherequiredEb/N0relativetoasingleradiolink.Theamountofgainisafunctionofmobilespeed,diversitycombiningalgorithmusedinthereceiverandchanneldelayprofile.MoreabouttheSHOgaincanbefoundinSectionIIC.ReceiversensitivityestimationInthelinkbudgettheBSreceivernoisedensityisestimatingthenoiseleveloveroneWCDMA—carrier.TherequiredreceiverSNRcontainstheprocessinggainandthelossduetotheloading.Theloadingusedisthetotalloadingduetodifferentservicesonthecarrierinquestion.Therequiredsignalpower(S)dependsontheSNRrequirement,receivernoisefigureandbandwidth.公式(10)Where公式(11)公式(12)whereNfisthereceivernoisefigure,KisBoltzmannconstant,Toistheabsolutetemperatureand刀istheloading.Insomecasesthebasicnoise/interferencelevelisfurthercorrectedwiththemanmadenoiseterm.ShadowingmarginandsofthandovergainestimationThenextstepistoestimatethemaximumcellrangeandcellcoverageareaindifferentenvironments/regions.TheRLBisestimatingthemaximumallowedisotropicpathloss,fromthatvalueaslowfadingmargin,relatedtothecoverageprobability,hastobesubtracted.Whenestimatingthecoverageprobabilitythepropagationmodelexponentandthestandarddeviationforthelog-normalfadingmustbeset.Iftheindoorcaseisconsideredtheindoorlossisfrom15dBto18dBandthestandarddeviationforlog-normalfadingmargincalculationissetto10-12dB.Inthecaseofoutdoorcoveragetypicalstandarddeviationvalueis7to8dB.Typicalpropagationconstantsrangefrom2.5to4.TraditionallytheareacoverageprobabilityusedintheRLBisforsinglecellcase[1].Therequiredprobabilityis90%to95%andtypicallythisleadsto7-8dBfadingmargin,dependingonthepropagationconstantandstandarddeviationofthelog-normalfading.TheEquation〔13〕estimatestheareacoverageprobabilityforsinglecellcase:公式〔13〕Pristhereceivedlevelatcelledge,nisthepropagationconstant,x0istheaveragesignalstrengththresholdando-isthestandarddeviationofthefieldstrength.InrealWCDMAcellularnetworksthecoverageareasofcellsoverlapandthemobilestationisabletoconnecttomorethanjustoneservingcell.Ifmorethanonecellcanbedetectedthelocationprobabilityincreasesandishigherthandeterminedforasingleisolatedcell.Analysisperformedin[2]indicatesthatifthearealocationprobabilityisreducedfrom96%to90%thenumberofbasestationsisreducedby38%,Thisnumberindicatesthattheconceptofmultiserverlocationprobabilityshouldbecarefullyconsidered.Inrealitythesignalsfromtwobasestationsarenotcompletelyuncorrelated,andthusthesofthandovergainisslightlylessthanestimatedin[2].In[3]thetheoryofthemultiservercasewithcorrelatedsignalsisintroduced:公式〔14〕wherePoutistheoutageatthecelledge,丫SHOisthefadingmargininthecaseofsofthandover,o-isthestandarddeviationofthefieldstrengthandfor50%correlationa=b=1/21/2.Withthetheorypresentedforexamplein[1]thisprobabilityatthecelledgecanbeconvertedtotheareaprobability.IntheWCDMAlinkbudgettheSHOgainisneeded.Thegainconsistsoftwoparts:combininggainagainstfastfadingandgainagainstslowfading.Thegainagainstslowfadingisdominatinganditisspecifiedas:公式〔15〕Ifweassume95%areaprobability,n=3.5andthestandarddeviationis7dBthegainwillbe7.3dB-4dB=3.3dB.Ifthestandarddeviationislargerandtheprobabilityrequirementhigherthegainwillbemore.CellrangeandcellcoverageareaestimationOncethemaximumallowedpropagationlossinacellisknown,itiseasytoapplyanyknownpropagationmodelforthecellrangeestimation.Thepropagationmodelshouldbechosensothatitoptimumdescribesthepropagationconditionsinthearea.Therestrictionsofthemodelarerelatedtothedistancefromthebasestation,thebasestationeffectiveantennaheight,themobileantennaheightandthefrequency.OnetypicalexampleformacrocellularenvironmentisOkumura-Hata.Equation〔16〕presentsanexampleOkumura-Hatapathlossmodelforanurbanmacrocellwithbasestationantennaheightof25m,mobileantennaheightof1.5mandcarrierfrequencyof1950MHz[4].

公式(16)Afterchoosingthecellrangethecoverageareacanbecalculated.Thecoverageareaforonecellinhexagonalconfigurationcanbeestimatedwith:公式(17)-ExampleofaWCDMARLB.Exempled'unbilandeliaisonradioWCDMA.ULDLTransmitsjpowerJ23.00l?72,97mW2097b=嗚遙酎“38dBmIX消ntenuainoouc18.00dHiCable/Iwxjylossr2.00d2.00呵TtarwmitierFIRP(Ind.losiEi)JK..97^=h+e-d473S曲恥Them〕工！iKHsedensity-174.00I-I74,WRMdvernniwfipurr58K一一8.00dBReceiverncisCdensily?169.而h=f+j■166,00dBm/H工power-10JJ3匕l(fā)Glag|fl(W>hdUm-3.01-|0,OTdB-Requiredhc/lo-17.12t-lOtog^EbVN/WAO)-j-7,71dBRecpjircisignalpower-im當(dāng)1=i+k^107.145dBmRxan必rma旦江咕IK.00m0.00dBi'JCaMe/bodyloss1.00n-200nCovejragcprohabilily(quid翎zmquiEmum.%的195.00nCcYtrEyiepr^Jbabilii)jndoor^rcmiirumcnL)0.000.00喘,Ouitki優(yōu)Irxalionj)nib^biliLy(cfilculaied)附62&5出2%IndoorIcscationpmhabiiityfc蜀Idulul4?轂3332.“1儡envimnrrumc：vuidck?routdoorLognontialhikcnnslantoutdoor7.007.00杷LognormitlhdccunsiEiniindixjr12m12.00dBKropjigJti乃口nUidelex350Lognuriruilhdcniugm-7,27dB[Hnn&fMCr舐Im(injanyni眥小p2-00dBWhereSisthecoveragearea,risthemaximumcellrangeandKisaconstant,dependingonthenetworktopology.Thenumberofsectorsistypicallyfrom1to3.InthecaseofWCDMAreasonablevaluesareupto6sectors.Inthecaseof6sectorstheestimationofthecellcoverageareabecomesproblematic,sinceasix-sectoredsitedoesnotnecessaryresembleahexagon.Aproposalforthecellareacalculationatthisstageisthattheequationfortheomnicaseisusedalsointhecaseof6sectorsandthelargerareaisduetoahigherantennagain.Themoresectorsareusedthemorecarefulsofthandoveroverheadhastobeanalysedtoprovideanaccurateestimate.InTableIIsomeoftheK-valuesarelisted.--K-valuesforthesiteareacalculation.Valeursduparam-treKpourlecalculd'unezonedecouvertureautourd'unsite5JTECONFIG一1omniK1r-i26131952.6C.CapacityandcoverageanalysisintheinitialplanningphaseOncethesitecoverageareaisknownthesiteconfigurationsintermsofchannelelements,sectorsandcarriers,andsitedensity(cellrange)hastobeselectedsothatthesupportedtrafficdensitycanfulfiltherequirements.AnexampledimensioningcasecanbeseeninSectionIV.TheWCDMARLBisslightlymorecomplexthantheTDMAone.Thecellrangedependsonthenumberofsimultaneoususers(numberofchannels/usersintermsofinterferencemargin,seeEquation(6)).Thusthecoverageandcapacityareconnectedandalreadyintheverybeginningtheoperatorshouldhaveknowledgeandvisionofthesubscriberdistributionandgrowthsinceithasadirectimpactonthecoverage.Findingthecorrectconfigurationforthenetworksothatthetrafficrequirementsaremetandthenetworkcostminimisedisnotasimpletask.Thenumberofcarriers,numberofsectors,loading,numberofusersandthecellrangeallhaveanimpactontheresult.DETAILEDPLANNINGPROCESSIntroductiontoastaticradionetworkplanningsimulatorInthisstudythesimulatorfirstintroducedin[9]wasused.Itisofstaticnatureandneedsasinputsadigitalmap,thenetworklayoutandthetrafficdistributioninformofadiscreteusermap.Eachoftheuserscanhavedifferentterminalspeedandusesadifferentservice(bitrate,activityfactor,whichbothcanbedifferent'foruplinkanddownlink).ThereforeeachmobilestationgetsassignedanindividualEb/N0requirementimportedfromlinklevelsimulations.Thesimulatoritselfconsistsofbasicallythreeparts-initialisation,combineduplinkanddownlinkanalysisandpostprocessingphase.Followingtheinitialisationpart,roundafterroundinthemainpartofthetool,boththeuplinkanddownlinkforallmobilestationsareanalysedandaftertheiterationshavefuelledcertainconvergencecriteria,inthefinalstep,theresultsoftheuplinkanddownlinkanalysesarepostprocessedforvariousgraphicalandnumericaloutputs.Ontopoftheseresults,forselectedareas(whichalsocanconsistofthewholenetwork)areacoverageanalysesforULandOLdedicatedchannelaswellasforcommonchannels(commonpilotCPICH,broadcastcontrolchannel8CCH,forwardaccessandpagingchannelFACHandPCHontheP-CCPCHandS-CCPCH)canbeperformed.Incaseasecondcarderispresentinthenetworkarea,eitherusedbythesameoperatororbyanotheroperatoradjacentchannelinterference(ACI)canbetakenintoaccount.Onlyincasethesecondcarrierisassignedtothesameoperator,loadcanbesharedaccordingdifferentstrategiesbetweenthecarriers(IF-HO).Fig.Z.—staticsimulatoroverview.Vue加加’律鈦siutiqi4e.InitialisationPhaseIntheglobalinitialisationphasethenetworkconfigurationisreadinfromparameterfilesforbasestations,mobilestationsandthenetworkarea.Somesystemparametersaresetandpropagationcalculationsareperformed.Inthefollowingstep,requirementscomingfromthelinklevelsimulationsareassignedtobasestationsandmobilestations.Aftersomeinitialisationtasksfortheiterativeanalysis-settingdefaulttransmitpowersandnetworkperformance-theactualsimulationcanstart.C.CombineduplinkanddownlinkanalysisC1.UplinkiterationstepThetargetintheuplinkiterationistoallocatethemobilestations'transmitpowerssothatthe(interference+noise)-levelsandthusthebasestationsensitivityvaluesconverge.TheaveragetransmitpowersofthemobilestationstoeachbasestationareestimatedsothattheyfulfilthebasestationsEb/N0requirements.Theaveragemobilestations'transmitpowersarebasedonthesensitivitylevelofthebasestation,service(datarate)andspeedofthemobilestationandthelinklossestothebasestations.Theyarecorrectedbytakingintoaccountthe10activityfactor,thesofthandovergainsandaveragepowerraiseduetofasttransmitpowercontrol.Theimpactoftheuplinkloadingonthebasestationsensitivity(noiserise)istakenintoaccountbyadjustingitwith(l-4).“canbedefinedbyEquation(5).AftertheaveragetransmitpowersofthemobileshavebeenestimatedtheyarecomparedtothemaximumvalueallowedandmobilesexceedingthislimitaretryingIF-HOifallowedorareputtooutage.Nowtheinterferenceanalysiscanbeperformedagainandthenewloadingandbasestationsensitivitiesarecalculateduntiltheirchangesaresmallerthanspecifiedthresholds.Alsoincasetheuplinkloadingofacellexceedsspecifiedlimits,mobilestationsaremovedtoanothercarrierifallowed(IF-HO).Otherwisetheyareputtooutage.C2.DownlinkiterationstepSimilarlytotheuplinkthegoalofthedownlinkiterationistoassignthebasestationtransmitpowersforeachlink(includingSHOconnections)amobilestationishavinguntilallmobilestationsreceivetheirsignalwiththerequiredcarrier-to-interference-ratio,C/I,definedbyEquation(18)公式(18)whereEbNoMSisthereceivedEb/N0requirementoftheMSdependingonterminalspeedandservice.Theactualreceived(C/I)mofMSmiscalculatedusingMRCaccordingEquation(19)bysummingtheC/Ivaluesofalllinksk,k=1...Kmobilestationmishaving.公式(19)wherePkisthetotaltransmitpowerofthebasestationtowhichlinkkisestablished,Lpkmisthelinklossfromthecellktothemobilestationm,akisthecellspecificorthogonalityfactor,Pkmisthepowerallocatedtothelinkfrombasestationktomobilestationm,I°th,mistheothercellinterferenceandNmisthebackgroundandreceivernoiseofMSm.TheinitialtransmitpowersareadjustediterativelyaccordingthedifferencebetweentheachievedandthetargetedC/Ivalueuntilconvergenceisachieved.Theprocessrequiresiteration,sincetheC/Iateachmobilestationisdependentonallthepowersallocatedtotheothermobilestationsanditisnotknownaprioriwhetheralinkcanbeestablishedornot.IncaseeithercertainlinkpowerlimitsorthetotaltransmitpowerofabasestationisexceededmobilestationsareperformingIF-HOifallowedortakenoutrandomlyfromthenetwork.InafurtherstepforeachmobilestationitischeckedwhetherthereceivedEc/Iovalueisaboveauserdefinedthresholdsothatthemobilestationcan11

reliablymeasurethebasestationandsynchronisetoit.Alsohereifthethresholdgivenisexceeded,themobilestationtriesIF-HOorisputtooutage.AflowchartforthedetailediterationstepscanbeseenfromFigure3.號chart

Upink?lir-itonsrepCb-IcSIiCb-IcSIiLJnkxm-ckjftchr)a也ihkiflQHfund-pcuh**Lmi■tMVUllItMWRMKVIiItetrfiAHMULTM祟Ed3時m田=3bn?od?dME,adfiJ-OownsX底a-