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1、238IEEETRANSACTIONSONVEHICULARTECHNOLOGY,VOL.VT-29,NO.2,MAY1980AdvancedMobilePhoneServiceFRANKLINH.BLECHER,FELLOW,IEEEAbsrrac-Theadvancedmobilephoneservice(AMPS)system,anFMtransmissionfacilities.Eachvoiceradioatthecellsiteiscellularradiosysteminthefinalstagesofdevelopment,isdescribed.Acon
2、nectedtotheMTSOviaavoicefrequencytrunk.InbriefdescriptionofthesystemisfoUowedbyadisclrpsionofthecontroladdition,2400-bit/sdatalinksbetweentheMTSOandeachalgorithmswhicharebasictoitsoperation.Finally,astahreportisofthecellsitesareusedforthetransmissionofdigitalcontrolpresentedontheChicagode
3、velopmentalsystem(anoperationalcellularsystem)andthecellulartestbedinNewark,NJ(afieldlaboratoryusedtosignals.evaluatetheradiiperformanceofFMceUularsystemswithcellsassmaUasInamatureAMPSsystem’suchasshowninFig.1,direc-1.4-miradius).tionalantennasareemployedwithanRFbeamwidthof120”.Consequent
4、ly,eachcellsitehasthreedirectionalantennasfortransmissionandthreepairsofreceivingdirectionalINTRODUCTIONantennasinordertoprovide360”ofcoverage.AmaximumTHEadvancedmobilephoneservice(AMPS)systemwasof32radiochannelscanbeassignedtoeachdirectionaltosatisfythefollowingobjectives:antenna.Theuseo
5、fdirectionalratherthanomnidirectionalantennasprovidesa4-5dBsignal-to-interferenceadvantage1)nationwideservice,andmakesasevencellclusterfrequencyreusepatternpos-2)efficientuseofallocatedfrequencyspectrum,sible[2].3)servicequalityapproachingthewirelinenetwork,Asamobileinthecallingstatemoves
6、abouttheservice4)technicalandeconomiccapabilityofoperatinginarea,a“location”measurementismadeeveryfewsecondsserviceareasassmallasthousandsofusersandaslargebytheservingcellsite.Thismeasurementdeterminesiftheashundredsofthousandsofusers.currentlyservingdirectionalantennashouldcontinueinthis
7、Itisevidentfromthefourthobjectivethat,notonlymustroleorifthemobileshouldbe“handed-off”toanotherahighcapacitymobilesystembecapableofservinglargedirectionalantennaassociatedwiththesamecellsiteortonumbersofsubscribers,butthecapitalinvestmentandanothercellsite.Bythismea
