基于Matlab的Welch法功率谱估计

252()Vo.l25No.220076JournalofHubeiInstituteforNationalities(NaturalScienceEdition)Jun.2007:2006-12-11.:(MZZ04004).:(1979-),,,Matlab.MatlabWelch1,2(1.湖北民族学院信息工程学院,湖北恩施445000;2.湖北民族学院理学院,湖北恩施445000):在经典谱估计领域,由Welch提出的修正周期图法获得了有效的应用,在多数情况下,其频率分辨率估计方差能满足实际应用.运用Matlab软件进行Welch算法仿真与分析,从而得出一些有价值的结论.:功率谱估计;周期图;窗函数;分辨率:TP311.13:A:1008-8423(2007)02-0215-02(PSE),,.MATLAB,,,MATLAB.WelchMATLAB.1WelchBarlettWelchNattall,WelchWelch,[1].Welch,,[2].,NL,M=N/L,,1/L,.(1):GLM()=Ll=1GM,l()/L(1)LM,.,LM,,.LM.,[3].2WelchMatlab2.1仿真实现Welch1.1WelchFig.1FlowchartofspectrumestimationofWelchmethodMatlabpsdpwelchWelch,,.Matlab,pwelch.:nfft=1024;window=harmming(100);noverlap=20;[Pxx,f]=pwelch(xn,window,noverlap,nfft,Fs);plot_Pxx=10*log10(Pxx);plot(,fplot_pxx)title(W'elch(hamming))'2Fig.2ThePSEofdifferentwindowfunctions2.2结果分析Harmming,ChebyshevRectangular,2.2,,Hamming,Chebyshev,Reclangular,,.[4].3MatlabWelch,,,,.,,,.:[1].MATLAB7[M].:,2005.[2],.[M].:,2006.[3],.[M].:,2004.[4],.MATLAB[J].,2000,28(4):45-48.AnalysisofWelchMethodinPSEBasedonMatlabLIUSong1,LUOMin2(1.SchoolofInformationEngineering,HubeiInstituteforNationalities,Enshi445000,China;2.SchoolofScience,HubeiInstituteforNationalities,Enshi445000,China)Abstract:Inthefieldofclassicalchar,ttheamendedperiodictableputforwardbyWelchisprovedtobeeffectiveinapplication.Undermanyconditions,itsfrequencydistinctionandestimatevariancecansatisfythepracticalapplication.ThispapergivesanexampletosimulatethemwithMatlab,analysestheperformancesofthesemethodsanddrawssomeusefulconclusions.Keywords:powerspectrumestimation;periodictable;windowfunction;resolution216()25