无线通信基础(双语)_教学课件_15.ppt

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1、ReviewofLastClass2、Frequencyreuseandmobilitymanagement1、FundamentalsofCellularCommunications3、CellclusterconceptChapter4----Lecture25、Callblockinganddelayatthecell-site4、Cochannelandadjacentchannelinterference6、Othermechanismsforcapacityincrease7、Channelassignmentstra

2、tegies2、Frequencyreuseandmobilitymanagement1、Introduction3、Cellclusterconcept4、CochannelandadjacentchannelinterferenceCochannelInterferenceAdjacentchannelinterference4.4CochannelandadjacentchannelinterferenceDeploymentoffrequencyreuseisnecessarytoenlargethesystemcapac

3、ity.Ontheotherhand,frequencyreusewillintroducecochannelinterferencefromcellsusingthesamesetoffrequencies.Therefore,frequencyneedstobecarefullyplannedsothatcochannelinterferenceiskeptatanacceptablelevel.CochannelInterference4.4CochannelandadjacentchannelinterferenceInt

4、erferencefromothermobilesatthecell-sitereceiverinthesamecellisintracellinterference,interferencefromothercellsisintercellinterference.CochannelInterference4.4CochannelandadjacentchannelinterferenceBaseStationForwardchannelordownlinkReversechanneloruplinkIntercellinter

5、ferenceinthedownlinkthataffectsthereceptionattheindividualmobilehostsmaybemoreofaproblemthanuplinkinterferenceatthecell-sitereceiverCochannelInterference4.4CochannelandadjacentchannelinterferenceForsimplicityinthefollowinganalysis,wewillconsideronlytheaveragechannelqu

6、alityasafunctionofthedistancedependentpathloss,withoutgoingintodetailsofchannelstatisticsduetopropagationshadowingandmultipathfading.CochannelInterference4.4CochannelandadjacentchannelinterferenceCochannelInterferenceTheaveragereceivedsignalstrengthatanypointdecaysasa

7、powerlawofthedistancebetweenthetransmitterandthereceiver.4.4CochannelandadjacentchannelinterferenceAssumingS----thepowerofthedesiredsignalI----thepowerofthecochannelinterferenceNI----thenumberofcochannelinterferingcellsIi----theinterferencecausedbytransmissionsfromthe

8、i-thinterferingcochannelcellbasestationCochannelInterference4.4CochannelandadjacentchannelinterferenceThesignal-to-cochannel