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2410JOURNALOFCHINAINSTITUTEOFCOMMUNICATIONSOctober2003200310Vol.24No.10WCDMA710049WCDMAOVSFTN929.533A1000-436X(2003)10-0046-09OptimaljointpowerandspreadinggainassignmentinthedownlinkofWCDMAsystemsWANGYong-gang,ZHUShi-hua,LVLing(Dept.ofInformationandCommunicationsEngineering,Xi’anJiaotongUniversity,Xi’an710049,China)Abstract:Ajointalgorithmoftransmitpowerandspreadinggainassignmenttotheusersisstudied.SpecificallyanoptimaljointpowerandspreadinggainassignmentschemeispresentedfortheWCDMAsystemswheretheorthogonalvariablespreadingfactor(OVSF)codesareusedandthenumberofthespreadingcodesislimited.Simulationresultsindicatethatwiththisscheme,theaggregatedatathroughoutofthesystemcanbeimproved,thequeuingtimebereduced,andthechannelutilizationbeimprovedremarkably.Keywords:CDMA;radioresourceassignment;spreadinggain;mobilecommunications1QoS2002-03-062003-05-22600720408632001AA1230411975-1950-1975-10WCDMA47WCDMAbest-effortDS-CDMAQoS[1~4][1][2,3]Eb/I0[2]Eb/I0[4]DS-CDMA112DS-CDMAWCDMAOVSF234WCDMA562#0jEb/I0Gj20sDdfG++=jjjjjjNPg(1)jgj#0jfj0P#0jNjdjD2s18#i()181,,iiiiPPPPL=18#00P1j482003()00PPjjjfad-=(2)18018202101PPPjjjjbbbD+++=L(3)jajbCDMA2300PPjjjjjfabDd-=+⋅(4)()181,,jjjjbbabL=41j0b/IE2000sfabfG+-⋅=PPNPgjjjjjjj(5)PsR[0,1]0b/IE/#0M[5]()()∑==MjjjMPNNS1s0,Gkf(6)k76fN∑=MjjP10f*0P(7)*0P#0352000sfabfG+-⋅=PPPgNjjjjjjj(8)6()()∑=+-⋅=MjjjjjjjjMPPPPgNS1s200001,GGsfabfkf(9)()gsP/fN10WCDMA49eg*()1maxarg=s**gggegP(10)eg0()ggsP9()()()∑∑==+-⋅≤+-⋅=MjjjjjjMjjjjjjjjMPPPgPPPPPgNS12000**s1s200001,sfabfggkGGsfabfkf(11)11jG*g()NSM,0f5*=gGjj()0200**PgPPNjjjjjjfsfabg+-⋅=j=1,2,M12*g10126jN0()()0200ss*PgPPPPNjjjjjjjjfsfabGG+-⋅′=(13)813()()jjjPPGGGss′=()()jjjPPGGGss′=gjG()(){}0argss*=′-=ggggPP(14)10()∑=+-⋅=MjjjjjjMPPPgF120000sfabfkf(15)*g11()fMF015()fMF0jf()()()3200202002sfabsbakff+-⋅+⋅=′′∂∂′′PPPPgFjjjjjjjM(16)502003j()0/0′′∂∂′′jMFff()fMF00jf()fMF0M-1015*02*00maxPPPgjjjjksab⋅⎪⎭⎪⎬⎫⎪⎩⎪⎨⎧+-⋅(17)17max()pilot0pilot2*000PSNRPPgjjj=+-⋅sab(18)()fMF012jfjNjNfjNj12WCDMA4WCDMACDMAWCDMASFminRnN2=min2R122/-=nNkn-2min2Rk[6]NCNN×NN-chip(){}NnnNCL,1=()nCNNnN2=NC2/NC()()()()()()()()()()()()()()()()()⎥⎥⎥⎥⎥⎥⎥⎥⎥⎦⎤⎢⎢⎢⎢⎢⎢⎢⎢⎢⎣⎡=⎥⎥⎥⎥⎥⎥⎥⎥⎦⎤⎢⎢⎢⎢⎢⎢⎢⎢⎣⎡-=2/2/2/2/2222111113212/2/2/2/2/2/2/2/2/2/2/2/NCNCNCNCCCCCCCCCNCNCCCCCNNNNNNNNNNNNNNNNNNMM1910WCDMA511()111=Ck2-chipk2k19WalshC1(1)={1}C2(1)={1,1}C2(2)={1,–1}C4(1)={1,1,1,1}C4(2)={1,1,–1,–1}C4(3)={1,–1,1,–1}C4(4)={1,–1,–1,1}C8(1)C8(2)C8(3)C8(4)C8(5)C8(6)C8(7)C8(8)SF=8SF=4SF=2SF=11SFjjSFN(20)1112()()*s1**s**01,gkgkfPNPNSMjM=⎟⎠⎞⎜⎝⎛∑=(21)WCDMA()*sgkPWCDMAa)pilotpilot2pilot1MSNRSNRSNRLb)1SF1=4*1N0*1Pf1*1SFN⋅=hpilot1*1pilot1*0*1SNRNPPgf=h*00*1PPfSF1=SF1/2*1N0*1Pfc)nSFnSFnSFn-1*nN0*PnfnnSFN⋅=h*pilot*pilot*0*nnnnSNRNPPgf=522003∑=njjPP1*00*fSFn=SFn/2*nN0*Pnfd)-∑+=111KjjSF1-SFK+1K+1e)a)~d)f)a)~d)d)53191000mWCDMA[7]3.84MHz0.543dBm15%1*g3dB3km/h10%dBm2.103-=WNt[7]RLlg6.374.137+=(22)Flg8dBFLPLlg+=(23)1[7]1SF481632641282565121/2kbit/s9364562151054520-246-121-3[8]()1+⋅=aaaxkxfxkxk,0,a(24)10WCDMA53[8]=81.51.1=a67kbit/s15session5PoissonFIFO1h24106050010001500200025003000350040001.01.52.02.53.03.5t/s1.64Mbit/s2.84Mbit/s/bits–10500100015002000250030003500400000.10.20.30.40.50.60.70.8t/s/s0.26s0.18s23100.45/s0.400.350.300.250.200.150.100.0501234567891042WCDMA2.84Mbit/s1.64Mbit/s65%31060s0.06s1/4410542003WCDMA6CDMAWCDMAOVSFWCDMA65%1/4WCDMA[1]CHIH-LI,SABNANIKK.VariablespreadinggainCDMAwithadaptivecontrolfortruepacketswitchingwirelessnetwork[A].ProcofIEEEInternatConfonComm(ICC’95)[C].Seattle,WA,USA,1995.2:725-730.[2]SAMPATHA,KUMARPS,etal.PowercontrolandresourcemanagementforamultimediawirelessCDMAsystem[A].ProcofIEEEInternatSymposiumonPersonal,IndoorandMobileRadioComm(PIMRC’95)[C].Toronto,Canada,1995.1:21-25.[3]RAMAKRISHNSS,HOLTZMANJM.Aschemeforthroughputmaximizationinadual-classCDMAsystem[J].IEEEJSelectedAreasComm,1998,16(6):830-844.[4]OHSJ,WASSERMANKM.Dynamicspreadinggaincontrolinmulti-serviceCDMAnetworks[J].IEEEJSelectedAreasComm,1999,17(5):918-927.[5]OHSJ,WASSERMANKM.AdaptiveresourceallocationinpowerconstrainedCDMAmobilenetworks[A].ProcofIEEEWirelessCommandNetworkingConf(WCNC’99)[C].NewOrleans,LA,USA1999.1:510-514.[6]DINANEH,JABBARIB.SpreadingcodesfordirectsequenceCDMAandwidebandCDMAcellularnetworks[J].IEEECommMagazine,1998,36(9):48-54.[7]HOLMAH,TOSKALAA,BothofNokia,Finland.WCDMAforUMTS,RadioAccessforThirdGenerationMobileCommunications[M].Chippenham:JohnWiley&Sons,Ltd,2000.[8]TEROO,RAMJEEP.WidebandCDMAforThirdGenerationMobileCommunications[M].Boston,Landon:ArtechHouse,1998.