Parametric adaptive time-frequency representation based on time-sheared Gabor atoms

(整期优先)网络出版时间:2007-01-11
/ 1
Alocalizedparametrictime-shearedGaboratomisderivedbyconvolvingalinearfrequencymodulatedfactor,modulatinginfrequencyandtranslatingintimetoadilatedGaussianfunction,whichisthegeneralizationofGaboratomandismoredelicateformatchingmostofthesignalsencounteredinpractice,especiallyforthosehavingfrequencydispersioncharacteristics.Thetime-frequencydistributionofthisatomconcentratesinitstimecenterandfrequencycenteralongenergycurve,withthecurvebeingobliquetoacertainextentalongthetimeaxis.Anovelparametricadaptivetime-frequencydistributionbasedonasetofthederivedatomsisthenproposedusingaadaptivesignalsubspacedecompositionmethodinfrequencydomain,whichisnon-negativetime-frequencyenergydistributionandfreeofcross-terminterferenceformulticomponentsignals.Theresultsofnumericalsimulationmanifesttheeffectivenessoftheapproachintime-frequencyrepresentationandsignalde-noisingprocessing.