基于DSP的2FSK实现-邱雅

286Vol128,No16西华大学学报(自然科学版)JournalofXihuaUniversity#NaturalScience200911Nov.2009:1673-159X(2009)06-0062-04:2009-03-12:(1981-),,,,()DSP2FSK邱雅,李兵,肖乐(,610039):DSP,DSP,TITMS320C67132FSK,,,,,:;DSP;;:TN911.72:ARealizationof2FSKModulationBasedonDSPChipQIUYa,LIBing,XIAOLe(SchoolofMathematicsandComputerEngineering,XihuaUniversity,Chengdu610039China)Abstract:DSPsarewidelyappliedinmoderncommunicationfield.AccordingtothesignalprocessingfeaturesofDSPs,thedigitalmodulationof2FSKsignalisrealizedbasedonthedigitaloscillator,whichiscomposedofDSPchipTMS320C6713offeredbyTIcom-pany.Sinusoidsignalisproducedbyiterationtechnique.Anddifferencedetectionalgorithmisusedfordemodulationof2FSKsigna.lComparingwithdigitalquadraturedemodulationalgorithm,theapproachomitslocalcarrierrecoveryandcostslesscomputation,soitiseasiertorealize.Simulationresultsshowthatthisapproachcanmeetthedesignrequirements.Keywords:frequencyshiftkeying;DSP;digitaloscillator;differencedetection0引言,DSPCPU,,DSP,FSK(FrequencyShiftKey)FSK,,FSK()[1]DSP2FSK,2FSK,,,TITMS320C67132FSK12FSK的工作原理111(2FSK):,f1f21f1,0f2,:S2FSK=[Enang(t-nTb)]cos(X1t)+[Enang(t-nTb)]cos(X2t)(1)(1),an=0P11-P,g(t)=010[t[TbX1=2Pf1,X2=2Pf2,anan,Tb6:DSP2FSK,,g(t)1,Tbf1f2[2]11122FSK2FSK2,,;,,,,,22FSK22FSK调制的DSP实现2112FSK2FSK,2FSKDSP,:fy[1]y[2],,1/fs(),[3]sin(kXT),ZH(z)=Cz-11-Az-1-Bz-2(2),A=2cos(XT),B=-1,C=sin(XT)0,Z:y[k]=Ay[k-1]+By[k-2]+Cx[k-1](3),sin(kXT)x[k-1],k=1,x[k-1]=1,:k=0y[0]=Ay[-1]+By[-2]+0=0k=1y[1]=Ay[0]+By[-1]+C=Ck=2y[2]=Ay[1]+By[0]+0=Ay[1]k=3y[3]=Ay[2]+By[1],,k=ny[n]=Ay[n-1]+By[n-2]k2,y[k]y[k-1]y[k-2],[4]XTS,y[n]TS,y[n]=sin(XnT),TMS320C6713DSP1600Hz3200Hz,01,1200bit/s,19200Hz(,52.08us,y[n]),(01600Hz,13200Hz):A0=2cos(X0T)=2cos(2P@1600/19200)=1.732050808B0=-1C0=sin(X0T)=sin(2P@1600/19200)=015A1=2cos(X1T)=2cos(2P@3200/19200)=1B1=-1C1=sin(X1T)=sin(2P@3200/19200)=018660254041600Hz3200Hz01,01600HzA0B0C0ABC;13200HzA1B1C1ABCDSP1600HZ3200HZy[1]y[2],y[1]y[2]y[2],63#20091600Hz3200Hz2122FSK19200Hz,TMS320C67133(CTLPRDCNT),1CTL21Timer0Timer1Timer20194000001980000014C0000CTL0194000401980004014C0004PRD0194000801980008014C0008CNT2CTL3112111098RsvdTSTATINVINPCLKSRCC/P76543210HLDGORsvdPWIDDATINDATOURTINVOUTFUNCC6000,CNT,PRD,[5]C6713CPU4CTLCLKSRC=1(),C/P=1(),FUNC=1(TOUT),PRDTINT:TSAT=f(clocksource)/(2*timerper-iodregister)(4)f(clocksource),DSPCPU1/42132FSK2FSK:-0.,1600Hz;-1.,3200Hz34CSL(ChipSupportLibrary)PLLEMIFTimerCSLC,CSL,,-0.-1.,y[1]y[2],,Ts,,,,32FSK432FSK解调的DSP实现2FSK,,,,,,[5],2FSK,55:S(n)kS(n-k),646:DSP2FSK,,2FSK2FSKX(n),S(n):S(n)=Asin(2PfnTs)=Asin(2Pf1nTs)-0.Asin(2PfnTs)-1.A,TSS(n),,k(k,S(n)S(n-k))S(n-k)S(n)S(n-k):V(n)=S(n)S(n-k)=Asin(2PfnTs)Asin[2Pf(n-k)Ts]=A22[cos(2PfkTs)-cos(4PfnTs-2PfkTs)](5),S(n)S(n-k)V(n),(5),I(n)=A22cos(2PfkTs),,K,:d(k)=|cos(2Pf1kTs)-cos(2Pf2kTs)|k=64实验结果DSPDSPCCS,CCS,2FSK6/00110010110000101001077,,,62FSK75结论DSP2FSK;,,,,,,,[1],.DSP(2FSK)[J].,2006,21(6):79-81.[2],.TMS320C54X2FSK[J].,2005(5):119-120.[3],.DSP[J].,2007,26(8):70-71.[4].TMS320C54202FSK[J].,2005(14):113-114.[5],.TMS320C6000DSPs[M],:,2003:498-499.[6],,.[J].,2008,5(1):80-83.(编校:邓英)65