频率精确测量方法研究

*X朱灿焰(苏州大学电子信息学院江苏苏州215021)=,,,FFT,=,,,:TM957.51:AResearchonthePrecisionMethodofFreuqencyMeasurementZHUCan-yan(ElectronicInfromationSchool,SoochowUniversityJiangsuSuzhou215021)=AbstractSeveralimportantwaystomeasuresignalfrequencyaregiven.Thephaseambiguity,whichisexistedinthephase-biasmethodisstudiedindetail.Amodifiedpreciselymeasuringmethodbeingcapabilityofphaseambiguityelimination,isthenproposed.Thesimulationresultsusingthreekindsoftechniques,i.e.FFTmethod,originalphase-biasmethod,andthemodifiedphase-biasmethod,arealsoparticularlygiven.Finallysomeconclusionsaremadeaccordingtotheresults.=Keywordsfrequencymeasuring,phaseambiguity,frequencyresolution,preciselymeasuring0引言,[1,2][3,4],,,,FFT,[5],,,1电子计数法1[3,4]:Vi;,,,T,fs,Tfs=NVi1fx=Mfs/N(1)MT1/TT,,,,,,?1,[2],,,2傅里叶变换方法:,,FFT,5426720047ModernRadarVol.26No.7July,2004X:2003-01-27:2003-04-29,fs,FFTN,(1),M,,,M(0~N/2-1)fs/NN,fs,,,FFT[6],,,,3相位差法FFT,,[5],FFT,[5]x(t)f0,X(f)=F[x(t)]=Ae-jUD(f-f0),w(t),X(k)=2N-1n=0x(nTs)W(nTs)e-j2PNnk=Aej5WG(k$f-f0)(2):WG(k$f-f0)w(t),Ts,$f=1/NTs=fs/N,U,A,X(k)x(t)y(t)=x(t-$T),$T.Y(f)=X(f)e-j2Pf0$T=Aej5D(f-f0)e-j2Pf0$T(3)y(t)w(t),Y(k)=Aej(5-2Pf0$T)WG(k$f-f0)(4)(2)(4),WG(k$f-f0),$5=argX(k)-argY(k)=2Pf0$T(5)f0=$52P#1$T(6),FFT,,,FFT;,FFT,,FFT[6],(5),,4相位模糊修正法及计算机模拟4.1FFT,,,[5],,2P,,(5),2Pf0$T,-2P~+2P,,(6)f0=2Pl?$52P$T,l=0,1,2,3,,(7)(7)1(7),,4.2,[2],,,,WG(k$f-f0),,2P,(7)(2)(4)Y(k)-X(k)=X(k)1e-j2Pf0$T-12=X(k)1-2jsin(Pf0$T)2e-jPf0$T(8)X(k)1Y(k)-X(k)2=jejPf0$T2sin(Pf0$T)(9)$H=arg1X(k)2-arg1Y(k)-X(k)2=12P+arg1º12+(Pf0$T)mod(2P)(10)557:,$H,Pf0$T,$H,:(1)WG(k$f-f0),$H,m,$H0,Pf0$T=2mP-$H;$H0,Pf0$T=2mP+$H(2)WG(k$f-f0),$H,m,$H0,Pf0$T=2mP+$H;$H0,Pf0$T=2mP-$H4.3,,1100Hz2.0kHz1.25MHz1fs=2.5678f0,Blackman51FFT3264128256512100HzFFT0.03710.00300.00300.00300.00200.97290.97290.97290.97290.97292.8277e-051.7296e-061.3005e-088.4652e-099.5218e-09200HzFFT0.03710.00300.00300.00300.00200.97290.97290.97290.97290.97292.8277e-051.7296e-061.3005e-088.4652e-099.5218e-091.25HzFFT0.03710.00300.00300.00300.00200.97290.97290.97290.97290.97292.8277e-051.7296e-061.3005e-088.4652e-099.5218e-009,5,FFT,22a2b;128,A2c23456Hz,N;2a2c10.0kHz2FFT5结论,FFT,,,FFT,[3,4],,[5],,,1,,,..:,19842...2000,28(12):99~1013..:,20004,.(2).:,19885...2000,22(5):41~446..:,1997男,教授主要研究方向为实时信号与信息处理软件无线电高速数字电子应用系统设计等5626