CDMAtechnical characteristics and development status.docx

CDMAtechnical characteristics and development status.docx

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CDMAtechnicalcharacteristicsanddevelopmentstatus

CDMA2000technicalcharacteristicsanddevelopmentstatus

Abstract

CDMA20001xisthemostmaturetechnology,business,andthefastestthird-generationmobilecommunicationtechnology.Technically,themosteffectiveresearchforwardandsofarthehighestthroughputofwirelesstechnologystandards.

Moreimportantly:

CDMAOne→CDMA20001x→CDMA20003x→CDMA20001xEV-DVevolutionwillbereal,frombasestationsthroughoutthenetworktothecorenetworkevolutioncompatiblelineoperatorstomaximizetheprotectionoftheinterests.Different2Gand3Gmobileterminalsinaseamlessroamingnetwork,usershavethegreatestdegreeofprotectioninterests.Itcanbepredictedthatinthelarge-scaleapplicationoftheCDMAOne,CDMA2000willbecomeoneofthemostcompetitive3Gtechnology.

Mobilecommunicationstechnologyinthedomesticdevelopmentofthesystembeganinthelate1990sMajorgroups’breakthrough;zhongxing,huaweianddatanghavelaunchedtheirsecond-generationGSMmobilecommunicationproducts.However,mobilecommunicationsnetworkequipmentmarketisaclearpreconceivedfeaturesGSMcordialbuildingatallforforeignequipment,todaystilldominatedbyforeignequipment.NationalGSMmobilecommunicationsindustryinthetechnicalbreakthroughdidnotbringthemarketbreakthrough.Accordingtostatistics,in1998thedomesticGSMequipmentmadeinChina,madeinChina;1999zerobasemarketshareof2.0%,4%ofmobileswitches.

May2001,thezhongxingCommunicationwiththesamelevelofself-developmentoftheCDMAbasestationsinternational,exchangeequipmentinthefirstphaseofChinaUnicom'sCDMAequipmenttender,scored10provinces,morethan110millionlinesofmarketshare,mobilecommunicationsequipmentismadeinChinaamajorbreakthrough.August2001,zhongxingCommunicationsopenedinhainandomesticfirstCDMA20001xtestingBureau.AfteryearsoftechnicalaccumulationtozhongxingCommunicationsrepresentedinthenationalcommunicationsindustrythird-generationmobilecommunicationtechnologyresearchanddevelopmentstrengthandthetechnicalbasiswithforeignmanufacturershavebasicallysynchronous.Thirdgenerationmobilecommunicationtechnologyinnationaldevelopmentcommunicationsindustryiscatchinguparareopportunityfortheinternationallevel.

1.theCDMA2000technologyoverview

Asathird-generationmobilecommunicationtechnologyofCDMA2000technologiesrepresentamajorevolutionfromCDMAOnecome.CDMA2000standardisastructureknownasCDMA2000family,whichcontainsaseriesofsub-standards.CDMAOneevolutionto3Gbytheway:

CDMAOne→（IS-95B）CDMA20001x（3x）,"CDMA20001xEV.FromCDMA20001x,whichisbelongtothethirdgenerationtechnology.Characteristicsofthevariousstagesofevolutionmeansrespectively

IS-95B:

tiedupbyeightvoicechannelsbusiness,providing64Kdataoperations.Inmostcountries,IS95Bbeencrossed,CDMAOnedirectlyfromtheevolutionofCDMA20001x.

CDMA20001x:

onthebasisoftheescalationinIS-95airinterfacesinahigh-speed307.2K1.25Mprovidebandwidthdatarates.

CDMA20003x:

5Machieve2Mbandwidthdatarates,aftertheCDMA20001xcompatibleandIS-95.

CDMA20001xEV:

enhanced1x,includingEV-DOandEV-DVtwophases.

2.ThetechnicalcharacteristicsofCDMA20001x

CDMA20001XwirelessinterfacesinalargesystemperformancethanIS-95increasingmainlyasfollows:

Supportrapidreplenishmentoftheoperationalchannels,individualaccesstothepeakrate3.7.2kbps；Priortotheintroductionofarapidcreditcontrol,andimproveaccesstothecapacityoftheformer；Launchsub-setsmannerOTD,increasedaccesstoresistdecline；Providinganti-guidesfrequencychannels,thereverseappearstodemodulatepossible,reversegains3dBincreaseoverIS95,reversecapacityisdoubled.

BusinesscorridorcouldJuanjicodemoreefficientthantheTurbocodetofurtherenhancecapacity.Introducedquicklycalledcorridors,andreduceconsumptionofmobileTaiwan,theTaiwanenhancedmobiledesignatedtime.Inaddition,newaccesswaystoreducethemovementofTaiwanaccessprocessinterferenceeffects,andenhancedaccesssuccessrate.SimulationresultsshowthattheoperationalcapacityCDMA20001XvoicesystemsIS95systemistwo-fold,IS-95dataandtheoperationalcapacityis3.2times.

CDMA20001XwirelessIPnetworkinterfacehasbeenusedapplicationsmature,openIETFagreementSimpleIPandMobileIPsupporttheInternet/IntranetaccesswaytoachieverealaccesstothemobileInternet.

Transmissionratefromthepointofview,thestandardratewillbeIS-95CDMA20001Xratesetsasubset（RC1,RC2）.Atthesametime,providingenhancedCDMA2000rate-set:

theformertoRC3-RC9,reverseRC3-RC6tomeetinahigh-speedthirdgenerationmobilecommunicationbusinessdatawhileachievingasmoothtransitionfromIS-95.CDMA20001XcanachieveontheCDMA（IS-95）systemfullycompatiblewiththetechnicalcontinuityofgoodreliabilityhigher.AlsofromthesecondgenerationtobecometheCDMA2000third-generationmobilecommunicationmostsmoothtransitionchoices.

3.CDMA2000abroadandbusinessprocessdevelopment

July2000,thebaseusedtopreparedemodulateQualcommCSM5000chipandmobilecomputersTaiwanDemodulateMSM5000chips,thefirstCDMA2000successfullyconductedthetwo-wayhigh-speedwireless-data153kbpsexperiments.TestresultsshowsthatinCDMA2000voicecapacity,datathroughput,phoneandwaitingtimeareobviousadvantages.

SamsungwasinAugust2000inSKTelecomsuccessfullylaunchedtheworld'sfirstCDMA20001XexperimentsBoard,andsubsequentlyLGTelecomandKTFreetelhaveeachlaunchedCDMA20001XBusinessBureau.Koreaisnowinlarge-scalecommercial,CDMA20001Xbasestationsmorethan4,700,asmanyas400,000usersofthe144kbpsdataservices.LucentandQualcomminearly2001successfullylaunchedCDMA20001XEV-DO（HDR）experiments,thesystembasedonLucentFlexentwirelessnetworkequipmentbusinesssupportwebsite,e-mailandotherapplicationsandvideostream.Transmissiondataratesupto2.4Mbpspersecond.Lucentplanstoachieveearly2002thebusinessofHDR.

MotorolaCompanyinApril2001throughtheinteractiveracinggameforthefirsttimedemonstratedaCDMAtechnology20001xEV-DVoneofthecandidates1XTREME.1.25MHzbandinthecertificationofitshigh-speeddatathroughputcapacityofupto4.8Mbps.

Inthemobilephoneterminals,SamsungCorporationhasseveralbusinesses1xmobilephonemarket;SamsungCorporationintroducedCDMA20001xmobilephoneSCH-X100andSPH-X1000sustainedairtimefor70-190minutes,waitingtimeat125-350hours.Datatransmissionratesofupto144Kbps,inadditiontoprovidingcolorvideotransmissiondynamics,avarietyofmultimediaservicessuchasVODandAOD.LG,SKTandMotorolacompanieshavelaunchedCDMA20001Xmobilephones.

IS-95AReverseChannelDiagram

Theprimaryfeaturesoftheforwardandreversechannelsaredescribedbelowinthesesections:

ChannelAssignmentinIS-95A；ForwardChannelCoding；BaseStationModulationandSpreading；BaseStationTransmitterInterface；CoherentRakeReceiver；ReverseChannelCoding；MobileStationWalshModulationandSpreading；NoncoherentRakeReceiver.

TheCDMAsystemrequiresspreadingofthespectrumusingaPNsequence.InIS-95A,therateofthisPNsequence（calledthechiprate）is1.2288Mchips/s.Thiscausestheresultingbandwidthofthespreadsignalstobeabout1.25MHz,whichisaboutone-tenthofthetotalbandwidthallocatedtoonecellularservicecarrier.

TheIS-95AsystemusestwoPNcodes:

TheshortPNcodeisapairofperiodicbinaryPNsequenceswithaperiodof215.

Thesesequencesareusedforspreadinganddespreadingsignalsintoin-phaseandquadraturecomponents.ThesameshortPNcodeisusedbymultiplebasestationsusingthesamefrequencybandbyusingdifferenttimingoffsetsinthecodecycle.

ThelongPNcodeisasequencewithaperiodof242-1,andthisisusedfor

spreadingonthereverselink,aswellasfordatascramblingandpowercontrolburstrandomization.

InadditiontothePNcodes,thereisasetoflength-64mutuallyorthogonalcodescalledtheWalshcode,whichisusedforensuringorthogonalitybetweenthesignalsfordifferentusersreceivingfromthesamebasestation.TheWalshcodeisalsousedformodulationforthereversechannelofIS-95A.Thus,thelogicalchannelontheforwardlinkisdeterminedbytheshortPNcodeoffset,theWalshcodeassigned,andtheassignedfrequencyofoperation.Onthereverselink,thelogicalchannelisdeterminedbytheshortPNcodeoffset,thelongcodeoffset,andtheassignedfrequencyofoperation.

TheIS-95Aforwardlinkusesseverallogicalchannels:

ThePilotchannelmodulatesaconstantsymbolandisusedforchannelestimation,whichallowsforcoherentdemodulationoftheotherchannelsthatcarryinformationbits.TheSyncchannelisusedforprovidingsynchronizationandconfigurationinformationtothemobilestations.ThePagingchannelsareusedforcontrolinformationandsendingpagingmessagestothemobilestation.TheTrafficchannelcarriesthespeechordata.

Similarly,thereverselinkhastheTrafficandAccesslogicalchannels:

TheAccesschannelismeantforcontrolinformation,andisusedfororiginatingrequests,respondingtopagingandothermessages,orprovidingotherdatatothebasestation.TheTrafficchannelcarriesthespeechordata.TheTrafficchannelsupportsvariabledatarateoperation.AccordingtotheJ-STD-008requirement,therearetwosetsofTrafficchanneldatarates.RateSet Ihasamaximumdatarateof9.6kbps,whereasRateSet IIhasamaximumdatarateof14.4kbps.Bothratesetssupportfull,half,quarter,ande