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25320075JOURNALOFAPPLIEDSCIENCESVol.25No.3May2007:2006206207;:2006207227:(60496311):,,:,E2mail:jzjang@sina.com;,,,:,E2mail:xh2yu@seu.edu.cn:025528297(2007)03202212061,2,1,1(1.,210096;2.,730070):,,,,.:;;;:TN929.5:AAHandoffModelinDistributedRadioMobileCommunicationSystemJIANGZhan2jun1,2,PANWen1,YOUXiao2hu1(1.NationalMobileCommunicationsResearchLaboratory,SoutheastUniversity,Nanjing210096,China;2.SchoolofElectronicandInformationEngineering,LanzhouJiaotongUniversity,Lanzhou730070,China)Abstract:AmodelforRAUselectionispresented,inwhichtheactiveset(AS)iscomprisedofselectedRAUsandservesforthemobilestation.Basedonthis,weproposeahandoffmodelindistributedradiomobilecommunicationsystem.Thereceivedsignalstrength(RSS)thresholdofhandoffiscontrolledbyaveragepoweroftheASadaptively.Performanceanalysisshowsthatnumericaldataobtainedfromthemodelareingoodagreementwithsimulationresults.Keywords:distributedradiomobilecommunicationssystem;handoff;RAUselectioncriterion;activeset(GN2cell),(RAU:remoteantennaunits)(BS:basestation)GN2cell.RAU,RAU(RF2cell),.,[1].,,[2,3].,RAU;,(MS)RAUBS.,(softhandoff).[4,5],(RSS).[6],;,[7].,[8],RAU,..[3],,,.(AS:activeset)RAU,,,.1[1]1,MSC.1GN2cell,GN2cellNRAU,GN2cell1iRAU(1)i,i=1,2,,N.,,ts,k,MSv,vtsMS.d(1)i(k)kMSRAU(1)i.1Fig.1Distributedradiomobilecommunicationssystem[4,5],,RSS,kMSRAU(j)iRSSs(j)i(k),j=1,2.s(j)i(k)=L(j)i(k)+u(j)i(k)=C1-10C2lg(d(j)i(k))+u(j)i(k)(dB)(1),L(j)i(k),C11m,C2,u(j)i(k),[10]E[ui(k)ui(k+n)]=2exp(-|n|tsvPdcorr)(2),dcorr,2,vMS.[9],.[3]ui(k)ui(k)=1-2zi(k)+ui(k-1)(3),=exp(-tsvPdcorr),zi(k)02,ui(k)zi(k).,RAUMS.2(AS)RAU,.2.1RAURAU3[11]:(addingthreshold)(drophysteresis)(drop2timer)RAUMSAS,Tadd,hdroptdrop,Tdrop=Tadd-hdrop.Tadd,hdroptdrop,AS,AS,.MSGN2cell1,kMSASSAS(k),RAU(1)iPSAS(k-1),s(1)i(k)Tadd,RAU(1)iSAS(k);RAU(1)iSAS(k-1),s(1)i(k)Tdrop,,RAU(1)iAS,s(1)i(k+tdrop)TdropRAU(1)iAS,s(1)i(k+m)Tadd,mtdrop,RAU(1)iAS,.MSAS,k,RAU(1)iSAS(k)RAU(1)iPSAS(k).RAU,RAU,,tdrop=Mts,RAU(1)iMarkov[11],2.222252kRAUiFig.2ThestatetransitiondiagramofRAUiattimek2(4),[11]p(1)i-,1(k)=P{s(1)i(k)TdropPs(1)i(k-1)Tadd}p(1)i-,2(k)=P{s(1)i(k)TdropPs(1)i(k-1)Tdrop}p(1)i+,1(k)=P{s(1)i(k)TaddPs(1)i(k-1)Tdrop}p(1)i+,2(k)=P{s(1)i(k)TdropPs(1)i(k-1)Tdrop}(4)(4),2,SAS(k)=M-1m=0Am(5)Pi,A(k)=(pi,A0(k),pi,A1(k),,pi,AM(k))MS2,Pi,A(0),Pi,A(k),RAU(1)ikMS,p(1)i(k)p(1)i(k)=P{RAU(1)iSAS(k)}=M-1m=0pi,AM(k)=p(1)i(k-1)+pi,AM(k-1)p(1)i+,1(k)-pi,AM-1(k-1)p(1)i-,2(k)(6)MSGN2cell1,kNi=1p(1)i(k).2.2CDMA,MSRAKE()ASRAU[10];,ASRAU,BTS.AS,,;().ASBS,MSCBS,.,,BS,MSGN2cellAS.1,MSGN2cell1GN2cell2,GN2cell1MS,:GN2cell2RAUMSAS,,GN2cell2MSAS,GN2cell1RAUMS.,GN2cell,,Tadd,RAU;,,.,AS(Tavg),kAS(7).MS,Tavg,;MS,Tavg,.Tavg(k)=10lgi(p(j)i(k)^L(j)i(k))ip(j)i(k)i{i/RAU(j)iSAS(k)}(7),jMS,^L(j)i(k)=10L(j)i(k)P10;ip(j)i(k)0,,SAS(k)=ª,AS,,,Tho(k)(8)Tho(k)=max(Tadd,Tavg(k))SAS(k)ªTaddSAS(k)=ª(8)Tho,(hysteresis),hadd,,[4,5].,(9),MSGN2cell1GN2cell2,(10),MSGN2cell2GN2cell13223,:max{s(2)i(k);i=1,2,,N}Tho(k)+hadd(9)max{s(1)i(k);i=1,2,,N}Tho(k)+hadd(10),k,GN2cellMS,3Markov.12MSGN2cell1GN2cell2;p2P1(k)p1P2(k)MSGN2cell1GN2cell2GN2cell2GN2cell1.3MSFig.3ThestatetransitiondiagramoftheMSattimekV(j)(k)=max{s(j)i(k);i=1,2,,NRAU};j=1,2,Th(k)=Tho(k)+hadd,s(j)i(k),p2P1(k)=P{V(2)(k)Th(k)PV(2)(k-1)Th(k-1)}=1-F(2)V(k)V(k-1)(Th(k-1),Th(k))PF(2)V(k-1)(Th(k-1))(11)p1P2(k)=P{V(1)(k)Th(k)PV(1)(k-1)Th(k-1)}=1-F(1)V(k)V(k-1)(Th(k-1),Th(k))PF(1)V(k-1)(Th(k-1))(12)(11)(12),F(j)V(k)(v)F(j)V(k)V(k-1)(v1,v2)V(j)(k)(CDF).F(j)V(k)(v)=P{V(j)(k)v}=P{max{s(j)i(k);i=1,2,,NRAU}v}=NRAUi=1P{s(j)i(k)v}=NRAUi=1v-Li(k)-fu(k)(x)dx(13)F(j)V(k)V(k-1)(v1,v2)=P{V(j)(k)v2,V(j)(k-1)v1}=P{s(j)i(k)v2,s(j)i(k-1)v1;i=1,2,,N}=NRAUi=1v2-L(j)i(k)-v1-L(j)i(k-1)-fu(k)u(k-1)(x1,x2)dx1dx2(14),fu(k)(x)fu(k)u(k-1)(x1,x2)u(k)(PDF).MSkGN2cell1GN2cell2p(1)in(k)p(2)in(k),p(1)in(k)=p(1)in(k-1)(1-p2P1(k))+(1-p(1)in(k-1))p1P2(k)(15)p(2)in(k)=p(2)in(k-1)(1-p1P2(k))+(1-p(2)in(k-1))p2P1(k)(16)p(1)in(k)+p(2)in(k)=1.kpho(k)=p(1)in(k-1)p2P1(k)+(1-p(1)in(k-1))p1P2(k)(17)Nho=Kk=1pho(k)(18),K.MSGN2cell1GN2cell2,p(1)in(0)=1,p(2)in(0)=0,(15)(18).kASNact(k)=2j=1p(j)in(k)Ni=1p(j)i(k)(19)34,GN2cell4RAU,MSv=10mPsAB.,,GN2cell.,MS10000.:ts=0.1s,tdrop=2ts,ds=vts=1m;C1=0dB,C2=3,=6dB,dcorr=20m,hdrop=1dB.4MSFig.4GN2cellstructureandMStrajectory5Tadd=-85dB,hadd=2dB,5(a)MSABGN2cell1,422250.5,;5(b);5(c)MS,,,.,,,,,.(a)(b)(c)5Fig.5Analysisdatacomparedwithsimulationresults(a)MSGN2cell1(b)MS(c)6hadd.,hadd.(COP:crossoverpoint)[4],COPMSGN2cell1GN2cell2MS,COP1000m.6(a)(b)haddp(1)in(k)pho(k),6(b)hadd,Nho,COP1000m.6(a)COP,:hadd=5dB,Nho=18.86,COP1003.7m,hadd=10dB,Nho=4.21,COP1013.8m,,hadd=15dB,Nho=1.32,,COP1061.6m.(a)(b)6haddTadd=-85dBFig.6AnalysisdatacomparisonwhenhaddisdifferentandTaddequals-85dB(a)MSGN2cell1(b)MS7Tadd,pho(k)ASNact(k).TaddNact,AS,AS,7(a);,AS(7)(8),Taddpho,Tadd,7(b),,,TaddNhoNact(tradeoff).(a)(b)7Taddhadd=2dBFig.7AnalysisdatacomparisonwhenTaddisdifferentandhaddequals2dB(a)(b)MS5223,:4,,,.,,Tho,Tadd,.,hadd,,,.:[1],.[J].,2004,32(12A):16-21.[2]ZHOUShidong,ZHAOMing,XUXinbin,WANGJing,YAOYan.Distributedwirelesscommunicationsystem:anewarchit