电信通信专业外文翻译译文

.PAGE.RadionetworkplanningprocessandmethodsforWCDMAWCDMA无线网络规划过程和方法AbstractThispaperdescribesthesystemdimensioningandtheradionetworkplanningmethodologyforathirdgenerationWCDMAsystem.Theapplicabilityofeachmethodisdemonstratedusingexamplesoflikelysystemscenarios.Thechallengesofmodelingthemultiserviceenvironmentaredescribedandtheimplicationstothesystemperformancesimulationsareintroduced.摘要本文详细介绍了系统的维数和第三代WCDMA系统无线网络规划方法。证明使用实例的可能的系统方案的每一种方法的适用性。描述了多业务环境中建模的挑战并且介绍了性能仿真对系统的影响。Keywords:Telecommunicationnetworkplanning,Mobileradio-communication,Codedivisionmultipleaccess,Widebandtransmission,Multipleservicenetwork,Dimensioning,Simulator,Staticmodel,Dynamicmodel,Cellularnetwork.关键词：电信网络规划,移动无线电通信,分码多重存取,宽带传输,多服务网络,维数,模拟器,静态模型,动态模型,蜂窝网络。Resume<?>ContentsIntroductionII.Initialplanning,systemdimensioningIII.DetailedplanningprocessIV.ExampledimensioningcaseandverificationofdimensioningwithstaticsimulationsV.ComparisonofastatictoadynamicnetworksimulatorVI.Conclusion目录产品简介初步规划,系统选型示例维数情况,在静态模拟下核实维数比较静态和动态网络模拟器结论INTRODUCTIONAsthelaunchofthirdgenerationtechnologyapproaches,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.产品简介推出第三代技术方法的同时,运营商正在形成他们的网络部署策略。无论在对未来服务需求的估计还是网络基础设施投资的要求,这些策略必须支持实际的业务计划。使用系统评估的无线接入和核心网络组件的尺寸工具,可以实现网络基础设施的要求评价。在发现了一个有吸引力的商业机会时,在系统部署之前,必须通过周密的网络规划。随着预期的流量配置文件加载时,网络规划工具必须能够准确模拟系统的行为。第三代蜂窝系统将提供的服务远远超出了今天的网络能力。当设计和规划一个基于第三代系统的WCDMA时,流量模板,以及无线接入技术本身形成两个最重要的挑战。流量模板描述了综合服务的用户群。也有特定的系统必须建模,包括快速功率控制和软切换的功能。为了准确预测无线覆盖与WCDMA系统相关的功能,必须考虑网络的建模过程。特别是沟道表征,并在CDMA系统的情况下,任何的干扰控制机制必须加以考虑。在WCDMA网络中多种服务并存。不同的服务〔语音,数据有不同的处理增益,Eb/N0的性能,因而有不同的接收器SNR的要求。除了那些WCDMA的覆盖范围取决于负载特性,交出的参数和电源控制效果都是如此。在当前的第二代系统的覆盖规划处理中,基站的灵敏度是恒定的,对每个基站的覆盖范围的阈值是相同的。在WCDMA的覆盖范围的阈值的情况下是依赖于用户的数量和在所有元件中使用的比特率,因此,这是元件和具体的服务。TheWCDMAplanningprocesscanbedividedintothreephases:initialplanning<dimensioning>,detailedradionetworkplanningandnetworkoperationandoptimization.Eachofthesephasesrequiresadditionalsupportfunctionslikepropagationmeasurements,KeyPerformanceIndicatordefinitionsetc.Inacellularsystemwherealltheairinterfaceconnectionsoperateonthesamecarrierthenumberofsimultaneoususersisdirectlyinfluencingonthereceivers'noisefloors.Therefore,inthecaseofVMTStheplanningphasescannotbeseparatedintocoverageandcapacityplanning.Inthecaseofthepostsecond-generationsystemsdataservicesstarttoplayanimportantrole.Thevarietyofservicesrequiresthewholeplanningprocesstoovercomeasetofmodifications.Oneofthemodificationsisrelatedtothequalityofservice<QoS>requirements.Sofarithasbeenadequatetospecifythespeechcoverageandblockingprobabilityonly.Alsomoreandmoreonehastoconsidertheindoorandin-carcoverageprobabilities.InthecaseofUMTStheproblemisslightlymoremultidimensional.ForeachservicetheQoStargetshavetobesetandnaturallyalsomet.Inpracticethismeansthatthetightestrequirementshalldeterminethesitedensity.InadditiontothecoverageprobabilitythepacketdataQoScriteriaarerelatedtotheacceptabledelaysandthroughput.Estimationofthedelaysintheplanningphaserequiresgoodknowledgeoftheuserbehaviourandunderstandinginthefunctionsofpacketscheduler.WCDMA规划的过程可以分为三个阶段：最初的规划〔尺寸,详细的无线网络规划和网络运营与优化。每个阶段需要额外的支持功能,如传播测量,关键绩效指标定义等。每个阶段需要其他的支持功能,如传播测量、关键绩效指标定义等。在蜂窝系统中,所有的空中接口连接在同一载波上运行,并发用户数直接影响接收机的噪声层。因此,在VMTS的情况下规划阶段不能被分离成覆盖和容量规划。在此后的情况下,第二代系统的数据服务开始发挥重要的作用。各种服务需要在整个规划过程中克服一系列修改。其中一项修改关系到相关的服务质量〔QoS要求。到目前为止,它已经足够指定语音覆盖和阻塞概率。此外,越来越多的人们必须考虑的是室内和车内覆盖概率。在UMTS的情况下,问题是稍微多维的。对于每个服务的QoS目标都必须设置.。在实践中,这意味着严格的要求应确定网站密度。除了覆盖概率的分组数据的QoS指标与可接受的延迟和吞吐量有关。在规划阶段的延迟估计需要用户行为的良好认知和理解数据包调度程序的功能。Commonfeaturesbetweensecondandthirdgenerationcoveragepredictionalsoexist.Inallthesystemsbothofthelinkshavetobeanalyzed.Incurrentsystemsthelinkstendtobeinbalancewhereasinthecaseofthirdgenerationoneofthelinkscanbehigherloadedthantheother,andthuseitheroneofthelinkscouldbelimitingthecellcapacityorcoverage.Thepropagationcalculationisbasicallythesameforallstandards,withtheexceptionthatdifferentpropagationmodelscouldbeused.Anothercommonfeatureistheinterferenceanalysis.InthecaseofWCDMAthisisneededfortheloadingandsensitivityanalysis,inthecaseofTDMA/FDMAitisessentialforfrequencyallocation.InordertofullyutilizetheWCDMAcapabilities,athoroughunderstandingoftheWCDMAairinterfaceisneededfromthephysicallayertothenetworkmodeling,planningandperformanceoptimization.第二代和第三代之间也存在覆盖预测的共同特点。在所有系统中两个链接是必须要进行分析的。在目前的系统中,连结往往是处于平衡状态,而在第三代的情况下的链接比其他加载更高,因此其中的链接可能会限制电池容量或覆盖。传播计算所有标准基本上是相同的,与此不同的是不同的传播模型被应用。另一个共同特点是干扰分析。在WCDMA的情况下,这是装载和敏感度分析所需要的,在TDMA/FDMA的情况下,对于频率分配它是必不可少的。为了充分利用的WCDMA能力,对WCDMA空中接口的透彻理解,需要来自物理层的网络建模,规划和性能优化。Inthispaperthepre-operationalphaseoftheWCDMAplanningprocess,asdepictedinFigure1indetail,isdiscussed.SectionIIisconcentratingontheinitialplanningissues.TheWCDMAlinkbudgetisintroducedanditisdemonstratedhowdifferentservicesandtheirQoSrequirementsimpactonthesitedensityestimate.InSectionIIIastaticradionetworksimulatorisintroduced.ThemethodologyrequiredinthecoverageandcapacityestimationforWCDMAisdescribedforbothuplinkanddownlink.TopicofSectionIVistodemonstratetheaccuracyofdimensioning:anexampleareaisdimensionedandtheaveragesitedistanceisdetermined.Thedimensioningresultiscomparedwiththeoutcomeofastaticnetworksimulation.InSectionVtheanalysismethodsofthestaticsimulatorareverified.Theverificationwasperformedwithadynamicsystemsimulator.ThepaperisconcludedinSectionVI.在本文中讨论了,图1中所详细描绘的运行前阶段的WCDMA规划过程。第二部分主要讨论最初的规划问题。介绍了WCDMA的链路预算并且证明了不同的服务和QoS要求对站点密度估计的影响。在第三部分介绍静态无线网络模拟器。上行链路和下行链路描述了用于WCDMA的覆盖范围和容量估计所需的方法。第四部分的一个主题是为了演示的尺寸精度,例如区域的尺寸和确定平均站点距离,将尺寸的结果与静态网络仿真的结果作对比。在第五部分验证了静态仿真分析方法。用一个动态的系统模拟器进行了核查。第六部分对本文做出总结。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.二。初步规划,系统尺寸初步规划〔即系统选型为网络元素数量以及这些元素相关的能力提供最早最快速的评估。这包括无线接入网络和核心网络。本文仅侧重于无线接入部分。初始规划阶段的目标是估计所需的站点密度和感兴趣地区的现场配置。初步规划活动包括无线链路预算〔RLB和覆盖分析、容量估计,以及最后对基站硬件和网站数量、无线网络控制器〔RNC、不同接口的设备、核心网络元素的估计。服务分布、交通密度、交通量的增长估计和QoS的要求是初步规划阶段必不可少的。在最初的规划阶段质量被考虑在阻塞和覆盖概率内。RLB计算完成每项服务,严格的要求应确定最大允许各向同性路径损耗。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=lKwhereKnisthenumberofMSsconnectedtoBSn,N=NoW=NfkToWisthenoisepowerinthecaseofanemptycell,Nfisthereceivernoisefigure,kistheBoltzmannconstantandT0istheabsolutetemperature.WCDMA无线链路预算的具体项目在本节中讨论的是WCDMA的上行链路和下行链路预算。有必要估计一个单元格的最大范围的一个RLB计算。在RLB中要考虑天线增益、电缆损耗、分集增益、衰落余量、分集增益等。RLB计算的输出是最大允许的传播路径损耗,这种损耗确定返回的单元格的范围,从而需要大量的网站。也有少数的WCDMA的链路预算中的特定项可以与当前的基于TDMA的无线接入系统作比较,如GSM。这些措施包括干扰降解保证金、快衰落余量、发射功率增加和软切换增益。干扰退化利润率是元件装载的一个功能。系统中允许更多的加载,就要在上行链路中需要较大的干扰余量和越小的覆盖区域。上行负载,可以得出如下简单的推导进行服务活动V=1。为了移动台的MSK连接到一个特定的基站BSn,要用CDMA的Eb/N0基本方程找出所需的上行链路的发送和接收信号功率。通常简单的理论是假设Ioth,从连接到其他元件的移动站接收的干扰与Iown接收到的干扰信号成正比〔比例常数。假设该MSK使用比特率为RK,则Eb/N0的要求是PK和CDMA调制带宽为W。然后,第k个移动峰值,它是连接到在基站处的接收功率,必须至少是这样的。公式<1>k=lKKN是MSs连接到BSN的数,,N=NoW=NfkToW是一个空单元格情况下的噪声功率,Nf是接收机的噪声系数,k是玻耳兹曼常数,T0为绝对温度。Theinequalitiesin<1>areslightlyoptimisticbecauseitisassumedthatthereisnointerferencefromtheownsignal.Inrealitythisisnotexactlytrueinmultipathpropagationconditions.Equation<1>ishoweverstillchosentoavoidtakingmultipathinterferenceintoaccounttwice.I.e.,theEb/N0requirementsdeterminedfromlinklevelsimulationsarepresentedsothatN0meansonlynoiseandmultipathinterferenceisvisibleinhigherEb/N0requirementtoacertainBERperformance.Solvingtheinequalitiesasequalitiesmeanssolvingfortheminimumrequiredreceivedpower<sensitivity>,Pk:公式<2>IftheEquationsin<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"〔1中的不等式比较理想,因为它是假定不存在干扰的自身信号。在现实中,在多径传播条件下,这是不完全正确的。方然而程〔1仍选择避免两次考虑多径干扰。即让N0表示只有噪声和多径干扰,确定链路级仿真的Eb/N0要求更高的Eb/N0要求有一定的误码率。解决不平等等式意味着解决所需的最小接收功率〔灵敏度,PK：公式<2>k=lK如果方程〔2中的移动台的总和连接到为BSn的移动站则：公式公式<3>since/ow,=~Pk'Ifloadingisdefinedas公式<4>此加载定义可以被增强,从而包括增益和服务活动,V：公式<5>使用公式[12]中的上行链路负载估计公式<6>其中m是所使用的服务的数量。方程〔5和〔6之间的差异是由于,当PK<<Iown,〔6并没有包括,在推导从方程〔1中的分母是IownPK+iIow+Ñ而不是Iown+iIown+Ñ。Thedownlinkdimensioningisfollowingthesamelogicastheuplink.Foraselectedcellrangethetotalbasestationtransmitpoweroughttobeestimated.Inthisestimationthesofthandoverconnectionsmustbeincluded.Ifthepowerisexceededeitherthecellrangeoughttobelimited,ornumberofusersinacellhastobereduced.Fordownlinktheloading<ηDL>isestimatedbasedon公式〔7whereLPmiisthelinklossfromtheservingBSmtoMSi,LPniisthelinklossfromanotherBSn,toMSi,PiisthetransmitEb/N0requirementfortheMSi,includingtheSHOcombininggainandtheaveragepowerraisecausedbyfastpowercontrol,Nisthenumberofbasestations,Iisthenumberofconnectionsinasectorandαiistheorthogonalityfactordependingonmultipathconditions<α=1:fullyorthogonal>.公式：Theterm~"definestheiDL.n=l,n~:mLPniDirectoutputofthedownlinkRLBisthesinglelinkpowerrequiredbyauseratthecelledge.Thetotalbasestationpowerestimationmusttakeintoaccountmultiplecommunicationlinkswithaverage<LPmi>distancefromtheservingbasestation.Furthermore,themulticellenvironmentwithorthogonalitiesaishouldbeincludedinthemodeling.Moreonthedownlinkloadingandtransmitpowerestimationscanbefoundin[13].IntheRLBcalculationinuplinkdirectionthelimitingfactoristhemobilestationtransmitpower,indownlinkdirectionthelimitisthetotalbasestationtransmitpower.Whenbalancingtheuplinkanddownlinkserviceareasbothlinksmustbeconsidered.下行尺寸与上行尺寸按照同样的逻辑进行的。对于一个选定的单元格范围应该估计总基站发射功率。在此估计的软切换连接必须包括在内。如果电源被超出,则应该限制单元格范围或必须降低一个小区中的用户数。对于下行链路加载〔ηDL的基础估计公式〔7其中LPmi是从服务BSm到MSi的链路损耗,LPni是从另一个BSn到MSi链路损耗,Pi是微星传输的Eb/N0要求,包括SHO结合增益和控制快速功率引起的功率平均提高,N是基站的数量,I是在一个部分的连接数,αi是取决于多径条件下〔α=1：完全正交的正交因子。公式：Theterm~"definestheiDL.n=l,n~:mLPni直接输出的下行链路RLB是由在小区边缘的用户所需的单个链路功率。总基站功耗估算,必须考虑到到平均值〔LPmi距离从服务基站的多条通信链路。此外,与正交αi的多小区环境应包含在建模中。在[13]中可以找到更多下行链路上的负荷和传输功率估计。在RLB计算在中,上行链路方向上的限制因素是移动台的发射功率,在下行链路方向上的限制因素是总基站发射功率。必须考虑在平衡在上行链路和下行链路的服务区时的两个链接。Theinterferencedegradationmargintobetakenintoaccountinthelinkbudgetduetoacertainloadingη<eitherinuplinkordownlink>is公式<8>在链路预算中,考虑在一定的负荷η〔无论是在上行链路或下行链路的干扰退化边缘率是公式〔8FastfadingmarginorpowercontrolheadroomisanotherCOMAspecificitemintheRLB.Somemarginisneededinthemobilestationtransmissionpowerformaintainingadequateclosedloopfastpowercontrolinunfortunatepropagationconditionslikethecelledge.ThisisapplicableespeciallyforpedestrianuserswheretheEb/N0tobemaintainedismoresensitivetotheclosedlooppowercontrol.Thepowercontrolheadroomhasbeenstudiedmorein[6]and[7].Anotherimpactofthefastpowercontrolisthetransmitpowerincrease.Inthecaseofaslowlymovingmobilestationthepowercontrolisabletofollowthefadingchannelandtheaveragetransmittedpowerincreases.Inowncellthisisneededtoprovideadequatequalityfortheconnectionanddoesnotcauseanyharm,sinceincreasedtransmitpoweriscompensatedbythefadingchannel.Forneighbouringcellshoweverthismeansadditionalinterference.Thetransmitpowerincrease<TxPowerlnc>isusedtoreducethereuseefficiencyaccordingtoEquation<9>.InEquation<4>ishouldbereplacedwithtermTxPowerlnc×iincasethemobilestationtransmitpowerincreaseissignificant.快衰落余量或功率控制余量是在RLB中另一个CDMA特定项目。一定的余量需要在移动站中的发送功率保持足够的闭环传播条件,例如小区边缘的快速功率控制。这是适用的,特别是对于要维持的Eb/N0的更敏感的闭环功率控制的行人用户。功率控制余量在[6]和[7]已经进行了研究。快速功率控制的另外一个影响因素是增加发射功率。在缓慢移动的移动台的情况下,功率控制能够按照衰落信道和平均发送功率来的增加。这是需要在自己的元件提供足够的连接质量且不会造成任何伤害,因为发射功率的增加经过衰落信道进行补偿。然而对于相邻小区来说这意味着额外的干扰。发送功率增加〔TxPowerlnc根据公式〔9是用来降低的复用效率。如果移动台的发射功率的增加是显着的,则在公式〔4中i应该被替换为TxPowerlnc×I。公式〔9Softhandovergainisdiscussedalreadyin[3].Handovers-softorhard-providegainagainstshadowfadingbyreducingtherequiredfadingmargin.Duetothefactthattheslowfadingispartlyuncorrelatedbetweencells,andbymakinghandoversthemobilecanselectabettercommunicationlink.Furthermore,softhandover<macrodiversity>givesanadditionalgainagainstfastfadingbyreducingtherequiredEb/N0relativetoasingleradiolink.Theamountofgainisafunctionofmobilespeed,diversitycombiningalgorithmusedinthereceiverandchanneldelayprofile.MoreabouttheSHOgaincanbefoundinSectionIIC.软切换增益[3]中已经讨论。切换软、硬对阴影衰落提供增益,减少所需的衰落余量。由于事实上慢衰落是部分元件之间不相关的通过使越区切换的移动台可以选择一个更好的通信链路。此外,软切换〔宏分集给出了一个额外的增益减少到一个单一的无线链路所需的Eb/N0相对抗快衰落。增益量的移动速度是一个函数,用于在接收器和信道延迟分布的分集组合算法。第二节C可以找到更多关于SHO增益。ReceiversensitivityestimationInthelinkbudgettheBSreceivernoisedensityisestimatingthenoiseleveloveroneWCDMA—carrier.TherequiredreceiverSNRcontainstheprocessinggainandthelossduetotheloading.Theloadingusedisthetotalloadingduetodifferentservicesonthecarrierinquestion.Therequiredsignalpower<S>dependsontheSNRrequirement,receivernoisefigureandbandwidth.公式〔10Where公式〔11公式〔12whereNfisthereceivernoisefigure,ΚisBoltzmannconstant,Toistheabsolutetemperatureandηistheloading.Insomecasesthebasicnoise/interferencelevelisfurthercorrectedwiththemanmadenoiseterm.B.接收灵敏度估计在链路预算中的BS接收机噪声密度估计超过一个WCDMA载波的噪音水平。由于装载,所需的接收SNR中包含的处理增益和损失。由于不同的服务问题,使用的加载是载体上的总负载。信噪比要求接收器的噪声系数和带宽取决于所需要的信号功率〔S。公式〔10Where公式〔11公式〔12其中NF是接收机噪声系数,Κ是玻尔兹曼常数,To为绝对温度,η为加载。在某些情况下,基本的噪声/干扰水平进一步修正与人为噪声术语。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〔13Pristhereceivedlevelatcelledge,nisthepropagationconstant,x0istheaveragesignalstrengththresholdandσisthestandarddeviationofthefieldstrength.InrealWCDMAcellularnetworksthecoverageareasofcellsoverlapandthemobilestationisabletoconnecttomorethanjustoneservingcell.Ifmorethanonecellcanbedetectedthelocationprobabilityincreasesandishigherthandeterminedforasingleisolatedcell.Analysisperformedin[2]indicatesthatifthearealocationprobabilityisreducedfrom96%to90%thenumberofbasestationsisreducedby38%,Thisnumberindicatesthattheconceptofmultiserverlocationprobabilityshouldbecarefullyconsidered.Inrealitythesignalsfromtwobasestationsarenotcompletelyuncorrelated,andthusthesofthandovergainisslightlylessthanestimatedin[2].In[3]thetheoryofthemultiservercasewithcorrelatedsignalsisintroduced:公式〔14wherePistheoutageatthecelledge,γisthefadingmargininthecaseofsofthandover,σisthestandarddeviationofthefieldstrengthandfor50%correlationa=b=1/21/2.Withthetheorypresentedforexamplein[1]thisprobabilityatthecelledgecanbeconvertedtotheareaprobability.IntheWCDMAlinkbudgettheSHOgainisneeded.Thegainconsistsoftwoparts:combininggainagainstfastfadingandgainagainstslowfading.Thegainagainstslowfadingisdominatinganditisspecifiedas:公式〔15Ifweassume95%areaprobability,n=3.5andthestandarddeviationis7dBthegainwillbe7.3dB-4dB=3.3dB.Ifthestandarddeviationislargerandtheprobabilityrequirementhigherthegainwillbemore.C:阴影利润率和软切换增益估计下一个步骤是估计最大的单元格区域和在不同的环境/地区的单元覆盖区域。RLB估计了允许的最大各向同性路径损耗,从该值中减去与覆盖概率有关的慢衰落余量。当估计覆盖概率时,必须设置。传播模型的指数和对数正态衰落的标准偏差。如果在室内的情况下被认为是室内损耗从15dB到18dB,对数正态衰落裕度计算的标准偏差设置为10-12dB。在室外覆盖的情况下,典型的标准偏差值是7至8分贝。典型的传播常数的范围从2.5到4。RLB中使用的传统的区域覆盖概率是在单电池的情况下的,根据对数正态衰落的传播常数和标准偏差,所求的概率是90％至95％,这通常导致7-8分贝衰落余量。式〔13估计的面积覆盖率为单电池的情况下的概率：公式〔13Pr是在元件边缘的接收电平,n是传播常数,x0是平均信号强度阈值,σ是磁场强度的标准偏差。在实际的WCDMA蜂窝网络中,元件重叠的覆盖区域和移动台能够连接到超过一个服务小区。如果多个单元格可以被检测到的位置的概率增加,此概率高于确定为一个单一的孤立小区。[2]进行分析显示,如果区域位置的概率从96％减少到90％,那么基站数量减少38％,这个数字表明,应慎重考虑多服务器位置概率的概念。在现实中,从两个基站的信号不是完全不相关的,因此软切换增益略小于[2]中的估计。[3]中介绍了多服务器的情况下相关信号的理论。公式〔14其中,P是小区边缘中断,γ是在软越区切换的情况下的衰落余量,σ是磁场强度的标准偏差,且为50％的相关性为a=b=1/21/2。例如在[1]中提出的理论,这一小区边缘概率可以被转换为区域概率。在WCDMA链路预算的SHO增益是必要的。收益由两部分组成：增益对抗快衰落和慢衰落的增益对相结合。对慢衰落的增益支配,它被指定为：公式<15>如果我们假设95％区域的概率,n=3.5,标准偏差为7dB,增益为7.3dB-4dB=3.3dB.CellrangeandcellcoverageareaestimationOncethemaximumallowedpropagationlossinacellisknown,itiseasytoapplyanyknownpropagationmodelforthecellrangeestimation.Thepropagationmodelshouldbechosensothatitoptimumdescribesthepropagationconditionsinthearea.Therestrictionsofthemodelarerelatedtothedistancefromthebasestation,thebasestationeffectiveantennaheight,themobileantennaheightandthefrequency.OnetypicalexampleformacrocellularenvironmentisOkumura-Hata.Equation<16>presentsanexampleOkumura-Hatapathlossmodelforanurbanmacrocellwithbasestationantennaheightof25m,mobileantennaheightof1.5mandcarrierfrequencyof1950MHz[4].公式<16>Afterchoosingthecellrangethecoverageareacanbecalculated.Thecoverageareaforonecellinhexagonalconfigurationcanbeestimatedwith:公式<17>D：单元范围和小区覆盖范围估计一旦在单元格中所允许的最大传播损耗是已知的,所以容易适用于任何已知的单元格范围估计的传播模型。应选择在该区域的传播条件下描述最佳的传播模型。模型的限制与从基站的距离、基站有效天线高度,移动台天线高度和频率有关。宏蜂窝环境的一个典型的例子是Okumura-Hata。方程〔16提出了一个例子,Okumura-Hata城市宏蜂窝路径损耗模型的基站天线高度25M,移动天线高度1.5m,载波频率为1950兆赫[4]。公式〔16在选择单元格范围的覆盖区域可以计算出来。六边形结构的覆盖区域中的一个单元可估计：公式〔17TABLEI.-ExampleofaWCDMARLB.Exempled'unbilandeliaisonradioWCDMA.WhereSisthecoveragearea,risthemaximumcellrangeandKisaconstant,dependingonthenetworktopology.Thenumberofsectorsistypicallyfrom1to3.InthecaseofWCDMAreasonablevaluesareupto6sectors.Inthecaseof6sectorstheestimationofthecellcoverageareabecomesproblematic,sinceasix-sectoredsitedoesnotnecessaryresembleahexagon.Aproposalforthecellareacalculationatthisstageisthattheequationfortheomnicaseisusedalsointhecaseof6sectorsandthelargerareaisduetoahigherantennagain.Themoresectorsareusedthemorecarefulsofthandoveroverheadhastobeanalysedtoprovideanaccurateestimate.InTableIIsomeoftheK-valuesarelisted.TABLEII.--K-valuesforthesiteareacalculation.Valeursduparam~treKpourlecalculd'unezonedecouvertureautourd'unsiteCapacityandcoverageanalysisintheinitialplanningphaseOncethesitecoverageareaisknownthesiteconfigurationsintermsofchannelelements,sectorsandcarriers,andsitedensity<cellrange>hastobeselectedsothatthesupportedtrafficdensitycanfulfiltherequirements.AnexampledimensioningcasecanbeseeninSectionIV.TheWCDMARLBisslightlymorecomplexthantheTDMAone.Thecellrangedependsonthenumberofsimultaneoususers<numberofchannels/usersintermsofinterferencemargin,seeEquation<6>>.Thusthecoverageandcapacityareconnectedandalreadyintheverybeginningtheoperatorshouldhaveknowledgeandvisionofthesubscriberdistributionandgrowthsinceithasadirectimpactonthecoverage.Findingthecorrectconfigurationforthenetworksothatthetrafficrequirementsaremetandthenetworkcostminimisedisnotasimpletask.Thenumberofcarriers,numberofsectors,loading,numberofusersandthecellrangeallhaveanimpactontheresult.表一WCDMARLB的例子其中,根据网络的拓扑结构,S为在覆盖区域中,r是最大的单元格范围,K是一个常数。扇区数通常是1至3个。在WCDMA的情况下,合理的值是6个扇区。在6个扇区的情况下的覆盖区域的估计成为问题,因为一个六扇区站点没有必要像六边形。在此阶段的小区面积计算的提案是,全方位的情况下的方程也适用于在6个扇区的情况下和由于更高的天线增益引起的更大的区域。使用的扇区越多,那么对软越区切换系统开销的分析要更加小心,为了提供精确的估计。表表Ⅱ中的K值被列出。表II地盘面积计算的K值。E.容量和覆盖分析的初步规划阶段一旦网站覆盖区域被称为站点配置,无论在通道元素,行业和运营商,和站点密度〔单元格范围和交通密度,都必须进行选择以便能满足要求。在第IV节可以看到一个尺寸的情况例子。WCDMARLB比TDMA稍微复杂一点。单元格区域取决于并发用户数〔数量的频道/用户的干扰余量,见公式〔6。这样的覆盖范围和容量被连接并且操作者在最开始就对用户分布和增长具备应有的知识和远见,因为它的覆盖范围有直接的影响。寻找正确的网络配置使这样的交通要求得到满足并且网络成本最小化不是一个简单的任务。载波数,扇区数,加载,用户数和单元格范围都对结果有一个影响。III.DETAILEDPLANNINGPROCESSIntroductiontoastaticradionetworkplanningsimulatorInthisstudythesimulatorfirstintroducedin[9]wasused.Itisofstaticnatureandneedsasinputsadigitalmap,thenetworklayoutandthetrafficdistributioninformofadiscreteusermap.Eachoftheuserscanhavedifferentterminalspeedandusesadifferentservice<bitrate,activityfactor,whichbothcanbedifferent’foruplinkanddownlink>.ThereforeeachmobilestationgetsassignedanindividualEb/N0requirementimportedfromlinklevelsimulations.Thesimulatoritselfconsistsofbasicallythreeparts-initialisation,combineduplinkanddownlinkanalysisandpostprocessingphase.Followingtheinitialisationpart,roundafterroundinthemainpartofthetool,boththeuplinkanddownlinkforallmobile