一种用于脉冲星信号去噪的新方法

:20091106:(2007AA12Z323);(60772139);(2009PNTT08);(K50510020037):(1975),,,,Email:[e-mail]:10.3969/j.issn.10012400.2010.06.014孙景荣,许录平,王婷(西安电子科技大学电子工程学院,陕西西安710071):为改善脉冲星辐射脉冲信号的信噪比,提出了一种基于双谱重构的脉冲星信号消噪方法.该方法将含噪脉冲星信号变换到双谱域,利用删减滤波器分别对其双谱相位和幅值进行滤波处理,再根据滤波后的双谱重构信号的功率谱和相位.实验结果表明,该方法可有效地滤除脉冲星信号中的噪声,显著改善了信噪比.:脉冲星;删减滤波器;双谱重构;信号处理:TN911:A:10012400(2010)06105906NewdenoisingmethodforpulsarsignalSUNJingrong,XULuping,WANGTing(SchoolofElectronicEngineering,XidianUniv.,Xian710071,China)Abstract:Inordertoimprovethesignaltonoiseratio(SNR)ofthepulsarsignal,thispaperproposesadenoisingalgorithmbasedonbispectrumreconstructionforthepulsarsignal.First,thenoisypulsarsignalistransformedintothebispectraldomain.Thebispectrumphaseandamplitudearefilteredbythetrimmedfilter.Then,thepowerspectrumandphaseofthepulsarsignalcanberecoveredfromthefilteredbispectrum.Resultsindicatethatthismethodcaneliminatenoiseinthepulsarsignals,andimprovetheSNRnotably.KeyWords:pulsar;trimmedfilter;bispectrumreconstruction;signalprocessing,,[1].,.,.,,[23].,,.,(),[47].,.,,.,[8],,.,.201012376()JOURNALOFXIDIANUNIVERSITYDec.2010Vol.37No.61双谱定义[9].{x(n)},nZ,,,C3,x(1,2)=E[x(n)x(n+1)x(n+2)].(1)(1),Bx(w1,w2)=+!1=-!+!2=-!C3x(1,2)exp(-j(w11+w22)),(2)(2),w1∀,w2∀,w1+w2∀.:Bx(w1,w2)=Bx(w2,w1)=B*x(-w1,-w2)=B*x(-w2,-w1)=Bx(-w1-w2,w2)=Bx(w1,-w1-w2)=Bx(-w1-w2,w1)=Bx(w2,-w1-w2).(3),w2#0,w1w2,w1+w2∀,.(2):Bx(w1,w2)=X(w1)X(w2)X*(w1+w2),(4)X(w)=+!n=-!x(n)exp(-jwn)=X(w)exp[-j!(w)].(5)(5)x(n),!(w)=argX(w),X(w).Bx(w1,w2)=X(w1)X(w2)X(w1+w2),(6)∀x(w1,w2)=!(w1)+!(w2)-!(w1+w2)(mod),(7)Bx(w1,w2),∀x(w1,w2).,,,0.:Bx(w1,w2),(6)(7)x(n)X(w)X(w)!(w)(),x(n).,,,(6)(7),.2删减滤波器21M∃M,Bx(p,q),x1,x2,%,xM∃M,xi={Re(Bx(pi,qi));Im(Bx(pi,qi))},i=1,2,%,M∃M,pi(p-(M-1)/2,p+(M+1)/2),qi(q-(M-1)/2,q+(M+1)/2).Dk=M∃Mm=1xkxk-xmxm,k=1,2,%,M∃M,(8)&L1,xx.[8]x∋=1n(1-)n(1-)k=1xk,(9)xknk,x∋,,(0,1).(TPF)PTPF=xcx∋px∋p,(10)x∋p=1M∃M(1-)M∃M(1-)i=1x(i)p,(11)1060西安电子科技大学学报(自然科学版)第37卷xp={D1∀D2∀%∀DM∃M}.(12)(8)Dk(k=1,2,%,M∃M)(12),x(i)pDi.xc,PTPF.,=M∃M(1-),,[1,M∃M],,(0,1).22,,.,a,aTF.M∃My1,y2,%,yM∃M,y∋p=1aai=1yi,M∃Ma.3双谱重构算法,BLWMU()()[9].BLWMU,,,BLW.BLWBartelt,LohmanWirnitzer1984[10].(7)!(p+q)=!(p)+!(q)-∀x(p,q).(13)(13)1.1pq!(p+q)=!(p)+!(q)-∀x(p,q)10!(1)=!(1)+!(0)-∀x(1,0)11!(2)=!(1)+!(1)-∀x(1,1)!(2)20!(2)=!(2)+!(0)-∀x(2,0)21!(3)=!(2)+!(1)-∀x(2,1)!(3)22!(4)=!(2)+!(2)-∀x(2,2)!(4)30!(3)=!(3)+!(0)-∀x(3,0)31!(4)=!(3)+!(1)-∀x(3,1)!(4)32!(5)=!(3)+!(2)-∀x(3,2)!(5)33!(6)=!(3)+!(3)-∀x(3,3)!(6)40!(4)=!(4)+!(0)-∀x(4,0)41!(5)=!(4)+!(1)-∀x(4,1)!(5)#####N/40!(N/4)=!(N/4)+!(0)-∀x(N/4,0)!(N/4)N/41!(N/4+1)=!(N/4)+!(1)-∀x(N/4,1)!(N/4+1)#####N/4N/4!(N/2)=!(N/4)+!(N/4)-∀x(N/4,N/4)!(N/2)1,!(0)!(1).NX(p)=X(p)exp(-j!(p)),p=0,1,%,N-1,!(p)=-!(N-p),p=0,1,%,N-1,!(0)=0.1:!(2)=2!(1)-∀x(1,1),!(3)=!(2)+!(1)-∀x(2,1)=3!(1)-∀x(1,1)-∀x(2,1),#!(p)=!(p-1)+!(1)-∀x(p-1,1)=p!(1)-∀x(1,1)-∀x(2,1)-%-∀x(p-1,1),(14)1061第6期孙景荣等:一种用于脉冲星信号去噪的新方法(14),!(p)p!(1).,,!(1)=0.,1.,1,!(p),!(p),.,,exp{j!(p)}.exp{j!(p)}=Cqexp{j(!(q)+!(p-q)-∀x(p-q,q))},(15)C.,(6)X(p+q)=Bx(p,q)X(p)X(q),(16)1.X(0),(16)p=0,q=0,X(0)=Bx(0,0)1/3.NX(p)=X(p)exp(-j!(p)),p=0,1,%,N-1,X(p)=X(N-p),p=1,2,%,N-1,X(0)=N-1p=0x(p).,X(p),p=0,1,%,N/2,.BLW,X(p),X(p).X(p)=0,.,,.4双谱重构过程,:(1);(2);(3)BLW,;(4),.5实验结果B0329+54,1.M,M=3.,,:(1)RNRR=10&(lg∃21-lg∃22),∃21,∃22.RNRR,.(2)RASNR=1NNi=120&lg(Vm/Vi),Vii[3].(DBR)(TPF)(TPF+aTF),224.2DBRTPF(=7)TPF(=7)+aTF(a=7)RNRR00333119338224104RASNR2696923276283571853M35TPF(=7)M=3M=5RNRR119338736243RASNR32762826798434,3,M.,1062西安电子科技大学学报(自然科学版)第37卷图1脉冲星积累信号波形(RASNR=270667)图2直接双谱重建信号(DBR)图3TPF法重构信号(M=3,a=7)图4TPF法重构信号(M=5,a=7)图5TPF+aTF(M=3,a=7)法重构信号,.,M=3.2,RNRR,RASNR,TPFaTFRNRRRASNR,TPF,DBR.25,DBR.35,()5.,,,,.6总结,.,.,.,,.:[1],,,.[J].,2000,27(6):781785.1063第6期孙景荣等:一种用于脉冲星信号去噪的新方法NiGuangren,YangTinggao,KeXizheng,etal.AResearchontheTimingMethodandtheDevelopmentofMillisecondPulsars[J].JournalofXidianUniversity,2000,27(6):781785.[2],,.[J].,2008,24(1):1821.KeXizheng,WangLi,NiGuangren.ApplicationofImprovedThresholdDenoisingBasedonWaveletTransformtoPulsarSignalProcessing[J].JournalofXianUniversityofTechnology,2008,24(1):1821.[3],,.[J].,2007,41(10):11931196.YanDi,XuLuping,XieZhenhua.WaveletDenoisingAlgorithmBasedonFuzzyThresholdforPulsarSignal[J].JournalofXianJiaotongUniversity,2007,41(10):11931196.[4],,.[J].,1999,26(6):691699.JiHongbing,GaoXinbo,XieWeixin.StudyofBispectrumSignaturesofRadarTargetsandClassificationTechniques[J].JournalofXidianUniversity,1999,26(6):691699.[5],,.[J].(),2009,32(2):251253.ZhouMingyue,DuLimin,JiangWenlong.HOSbasedWaveletDenoisingAlgorithm[J].JournalofChangchunUniversityofScienceandTechnology(NaturalScienceEdition),2009,32(2):251253.[6],,.[J].,2008,57(10):66836688.XieZhenhua,XuLuping,NiGuangren.TimeOffsetMeasurementAlgorithmBasedonBispectrumforPulsarIntegratedPulseProfiles[J].ActaPhysicaSinica,2008,57(10):66836688.[7],,.[J].,2009,38(2):249252.LiuJin,MaJie,TianJinwen.PulsarSignalRecognitionBasedonWaveletandBispectra[J].InformationandControl,2009,38(2):249252.[8]LukinV,TotskyA,KurekinA,etal.SignalWaveformReconstructionfromNoisyBispectrumEstimationsPreprocessedbyVectorFilters[