简介：AlthoughHamilton'squaternionhasbeenintroducedsuccessfullyinestimatingfrequenciesoftwodimensionalharmonics,itwasdifficulttouseittoestimatefrequenciesoftwodimensionalharmonicsinadditivenoisebecausethemultiplicativerulesofHamilton'squaternionwerenotcommutative.Inthispaper,wepresentedanewideatosolvethisproblemandappliedittoarraysignalprocessing.First,wepresentedanotherdefinitionofoperationrulesofquaternion,whosemultiplicativeruleswerecommutative.Second,weappliedthisdefinitiontoconstructcorrelationmatrixofhypercomplexsignalmodelbasedonquaternionsoastorestrainadditivenoise.Finally,wegottheisomorphiccomplexmatrixofcorrelationmatrixofhypercomplexsignalmodeltoestimatefrequencies.Somesimulationsillustratedournewidea.

简介：Accordingtothebiasedanglesprovidedbythebistaticsensors,thenecessaryconditionofobservabilityandCramer-Raolowboundsforthebistaticsystemarederivedandanalyzed,respectively.Additionally,adualKalmanfiltermethodispresentedwiththepurposeofeliminatingtheeffectofbiasedanglesonthestatevariableestimation.Finally,Monte-Carlosimulationsareconductedintheobservablescenario.Simulationresultsshowthattheproposedtheoryholdstrue,andthedualKalmanfiltermethodcanestimatestatevariableandbiasedanglessimultaneously.Furthermore,theestimatedresultscanachievetheirCramer-Raolowbounds.

简介：Aimingathandlingcomplicatedmaneuversorotherunpredictedemergenciesforhypersonicglidevehicletracking,threecoupleddynamicmodelsofstateestimationbasedontheprioriinformationbetweenguidancevariablesandaerodynamicsarepresented.Firstly,theaerodynamicaccelerationactingonthetargetisanalyzedtorevealtheessenceofthetarget’smotion.Thenthreecoupledstructuresformodelingaerodynamicparametersaredevelopedbydifferentideas:thespiralmodelwithaharmonicoscillator,thebankmodelwithtrigonometricfunctionsofthebankangleandtheguidemodelwiththechangingruleofguidancevariables.Meanwhile,thecomparisondiscussionisconcludedtoshowthenoveltyandadvantageofthesemodels.Finally,aperformanceassessmentindifferentsimulationcasesispresentedanddetailedanalysisisrevealed.Theresultsshowthattheproposedmodelsperformexcellentproperties.Moreover,theguidemodelproducesthebesttrackingperformanceandthebankmodelshowsthesecond;however,thespiralmodeldoesnotoutperformthemaneuveringreentryvehicle(MaRV)modelmarkedly.

简介：Accuratetimedelayestimationisveryimportantinmultichannelnoisesuppressionsystems.Thispaperhasproposedanewmethodtoreducetheeffectofnoiseontheestimationoftimedelaybetweendifferentchannels.Ournewtimedelayalgorithmwillmoreconsiderablyreducetheestimationerror,comparedwiththeconventionalautocorrelationfunctionmethod.

简介：Anewadaptiveestimatorfordirectsequencespreadspectrum(DSSS)signalsusingfourth-ordercumulantbasedadaptivemethodisconsidered.Thegeneralhigher-orderstatisticsmaynotbeeasilyappliedinsignalprocessingwithtoocomplexcomputation.Basedonthefourth-ordercumulantwith1-Dslicesandadaptivefilters,anefficientalgorithmisproposedtosolvetheproblemandisextendedfornonstationarystochasticprocesses.Inordertoachievetheaccurateparameterestimationofdirectsequencespreadspectrum(DSSS)signals,thefirststepusesthemodifiedfourth-ordercumulanttoreducethecomputingcomplexity.Whilethesecondstepemploysanadaptiverecursivesystemtoestimatethepowerspectruminthefrequencydomain.Inthecaseofinterceptedsignalswithoutlargeenoughdatasamples,theestimatorprovidesgoodperformanceinparameterestimationandwhiteGaussiannoisesuppression.Computersimulationsareincludedtocorroboratethetheoreticaldevelopmentwithdifferentsignal-to-noiseratioconditionsandrecursivecoefficients.

简介：在收音机频率鉴定(RFID)系统，backscattered信号对干扰小、容易。RFID标签identi的表演?在干扰情形的阳离子在无差错的情形与那相比被降级。在这份报纸，一个新奇Mahalanobis距离估计(MDE)方法被建议联合估计标签和包错误率的数字(每)。当干扰正在损害观察信息时，MDE方法是由于它完成一个稳定的评价的能力有弹性的错误。建议方法由在观察结果之中考虑所有信息和关联在存在方法上完成显著地提高的精确性。MDE方法基于观察信息的有效decorrelation和分类改进估计表演。而且，PER估计的表演在理论并且通过模拟被分析。它能从分析被结束估计了每不偏、围住变化。模拟证明建议估计以精确性和稳定性超过以前的建议，它在干扰情形为申请使它合适。

简介：Thetraditionalsuper-resolutiondirectionfindingmethodsbasedonsparserecoveryneedtodividetheestimationspaceintoseveraldiscreteanglegrids,whichwillbringthefinalresultsomeerror.Tothisproblem,anovelmethodforwidebandsignalsbysparserecoveryinthefrequencydomainisproposed.Theoptimizationfunctionsarefoundandsolvedbythereceiveddataateveryfrequency,onthisbasis,thesparsesupportsetisobtained,thenthedirectionofarrival(DOA)isacquiredbyintegratingtheinformationofallfrequencybins,andtheinitialsignalcanalsoberecovered.Thismethodavoidstheerrorcausedbysparserecoverymethodsbasedongriddivision,andthedegreeoffreedomisalsoexpandedbyarraytransformation,especiallyithasapreferableperformanceunderthecircumstancesofasmallnumberofsnapshotsandalowsignaltonoiseratio(SNR).

简介：Inanactiveradar-trackingsystem,thetarget-motionmodelisusuallymodeledintheCartesiancoordinates,whiletheradarmeasurementusuallyisobtainedinpolar/sphericalcoordinates.Thereforethetarget-trackingproblemintheCartesiancoordinatesbecomesanonlinearstateestimationproblem.Anumberofmeasurement-conversiontechniques,whicharebasedonpositionmeasurements,arewidelyusedsuchthattheKalmanfiltercanbeusedintheCartesiancoordinates.However,theyhavefundamentallimitationstoresultinfilteringperformancedegradation.Infact,inadditiontopositionmeasurements,theDopplermeasurementorrangerate,containinginformationoftargetvelocity,hasthepotentialcapabilitytoimprovethetrackingperformance.AfilterisproposedthatcanuseconvertedDopplermeasurements(i.e.theproductoftherangemeasurementsandDopplermeasurements)intheCartesiancoordinates.ThenovelfilteristheoreticallyoptimalintheruleofthebestlinearunbiasedestimationamongalllinearunbiasedfiltersintheCartesiancoordinates,andisfreeofthefundamentallimitationsofthemeasurement-conversionapproach.Basedonsimulationexperiments,anapproximate,recursiveimplementationofthenovelfilteriscomparedwiththoseobtainedbyfourstate-of-the-artconversiontechniquesrecently.Simulationresultsdemonstratetheeffectivenessoftheproposedfilter.

简介：TheBayesianapproachisconsideredasthemostgeneralformulationofthestateestimationfordynamicsystems.However,mostoftheexistingBayesianestimatorsofstochastichybridsystemsonlyfocusontheMarkovjumpsystem,fewliteratureisrelatedtotheestimationproblemofnonlinearstochastichybridsystemswithstatedependenttransitions.Accordingtothisproblem,anewmethodologywhichrelaxesquitearestrictiveassumptionthatthemodetransitionprocessmustsatisfyMarkovpropertiesisproposed.Inthismethod,ageneralapproachispresentedtomodelthestatedependenttransitions,thestateandoutputspacesarediscretedintocellspacewhichhandlesthenonlinearitiesandcomputationallyintensiveproblemoffline.ThenmaximumaposteriorestimationisobtainedbyusingtheBayesiantheory.Theefficacyoftheestimatorisillustratedbyasimulatedexample.

简介：SNRestimationofcommunicationsignalsisimportanttoimprovedemodulationperformanceandchannelqualityofcommunicationsystem,thusitisanimportantresearchissueofcommunicationfield.AccordingtothecoreproblemofautocorrelationmatrixsingularvalueinSNRestimationprocess,throughmakinguseofhouseholdertransformingautocorrelationmatrixintotridiagonalmatrix,andbyusingtherelationofcorrespondingcharacteristicequationcoefficientsandsingularvalue,anumericalalgorithmisgi...

简介：BlockmatchinghasbeenusedformotionestimationandmotioncompensationintheAu-dioandVideoStandard(AVS)foryears.Whilehavinganacceptableperformanceindescribingmo-tionbetweenframes,itrequiresquiteafewbitstorepresentthemotionvectors.Incertaincircum-stances,theuseofglobalmotionestimationandcompensationwouldperformequallywellorevenbetterthantheblockmatchingintermsofmotionaccuracy,whileitresultsinthecodingofglobalmotionmodelparameters.Inthisletter,wemodifyanAVScoderbyadding(1)sixglobalmotionmodelparameterstotheframeheader,and(2)modeselectionamongINTRA,SKIP,INTER-16×16,INTER-16×8,INTER-8×16,INTER-8×8,andGlobalMotionCompensation(GMC)modesbyLa-grangeoptimalrate-distortioncriteria.Simulationresultsdemonstratethatover0.1dBimprovementinPSNRisobtainedcomparedtotheAVScoderforanaveragecodedP-framewiththesamebit-rate.

简介：ThephaseestimationbasedonM-thpoweralgorithmisemployedinadifferentialquadraturephase-shiftkeying(DQPSK)coherentopticalfibercommunicationsystem,andthesystemperformanceimprovementisinvestigatedthroughnumericalsimulations.Itisfoundthattheapplicationofphaseestimationalgorithmcanrestrainthephasenoiseinducedbylaserlinewidthandfibernonlineareffects,andrecoverthecarrierphase,sothetransmissiondistanceofa40Gb/sDQPSK-RZsystemcanbeextendedtomorethan1300kmwiththeBERbelow10-12.

简介：

简介：Ahybridpilotsassistedchannelestimationalgorithmformultipleinputmultipleoutput(MIMO)orthogonalfrequencydivisionmultiplexing(OFDM)systemsunderlowsignal-to-noiseratio(SNR)andarbitraryDopplerspreadscenariosisproposed.Motivatedbythedissatisfactoryperformanceoftheoptimalpilots(OPs)designedunderstaticchannelsovermultipleOFDMsymbolsimposedbyfastfadingchannels,theproposedschemefirstassumesthatthevirtualpilottonessuperimposedatdatalocationsoverspecificsubcarriersaretransmittedfromallantennas,thenthevirtualreceivedpilotsignalsatthecorrespondinglocationscanbeobtainedbymakingfulluseofthetimeandfrequencydomaincorrelationsofthefrequencyresponsesofthetimevaryingdispersivefadingchannelsandthereceivedsignalsatpilotsubcarriers,finallythechannelparametersarederivedfromthecombinationoftherealandvirtualreceivedpilotsignalsoveroneOFDMsymbolbasedonleastsquare(LS)criterion.SimulationresultsillustratethattheproposedmethodisinsensitivetoDopplerspreadandcaneffectivelyamelioratethemeansquareerror(MSE)floorinherenttothepreviousmethod,meanwhileitsperformanceoutmatchesthatofOPsatlowSNRregionunderstaticchannels.

简介：Anewhybridwavelet-Kalmanfiltermethodfortheestimationofdynamicsystemisdeveloped,Usingthismethod,thereal-timemultiscaleestimationofthedynamicsystemisimplemented,andtheobservationequationestablishedisfortheobjectsignalitselfratherthanitswaveletdecomposition.Thesimulationresultsshowthatthismethodcanbeusedtoestimatetheobject'sstateofthestackedsystem,whichisthefoundationofmultiscaledatafusion;besidestheperformanceofthenewalgorithmdevelopedintheletterisalmostoptimal.

简介：ThispapergivesaMUSICsignalDOAestimationalgorithmbasedonthemodifiedhigh-ordercumulantmatrixwhichisconstructedbytherecieveddataandtheirconjugaterearrangements.Whenthesnapshotnumberislimited,thisalgorithmcanimprovethesignalDOAestimationperformancesobviously,anditscomputationalcomplexityscarcelyincreases.Finally,somesimulationresultstoverifythetheoreticalanalysesarepresented.

简介：Consideringthejointchannelestimationanddatadetectionintime-varyingorthogonalfrequencydivisionmultiplexing(OFDM)andaddressingtransmissionperformancedegradationinducedbythesevereinter-carrierinterference(ICI)atveryhighspeed,anewprogressiveiterativechannelestimationschemeisproposed.ToalleviatetheerrorpropagationoftheinaccuratedataduetoICI,themeasurementsubcarriersintheKalmanfilterisdesignedtobeextendedfrompilotssubcarrierstoallthesubcarriersprogressivelythroughtheiterations.Furthermore,initerationprocess,theinterferenceofthenon-pilotdatatothemeasurementsubcarriersisconsideredtobepartofnoiseinthemodifiedKalmanfilter,whichimprovestheestimationaccuracy.Simulationindicatesthattheproposedschemeimprovestheperformanceinfasttime-varyingsituation.

简介：多重信号分类(音乐)的表演关于仔细解决到达(DOA)的spaced方向的算法强烈取决于signal-to-noise比率(SNR)和快照。以便解决这个问题，由重建的一个方法有两噪音subspace的空间光谱函数和信号subspace在这份报纸被介绍。关键想法是使用在协变性矩阵包含的完整的信息并且改变分别地由他们的修订特征值在噪音和信号subspace上驾驶向量的设计重量。与MUSIC算法作比较，它也，并且显著地不增加任何计算复杂性，它有的优点同时减少噪音并且在低SNR和小样品下面保留高分辨率的能力大小的情形。模拟和实验结果被包括表明建议算法的优异表演。

简介：ThispaperconsiderstheBayesianandexpectedBayesian(E-Bayesian)estimationsoftheparameterandreliabilityfunctionforcompetingriskmodelfromGompertzdistributionunderType-Iprogressivelyhybridcensoringscheme(PHCS).TheestimationsareobtainedbasedonGammaconjugatepriorfortheparameterundersquarederror(SE)andLinexlossfunctions.Thesimulationresultsareprovidedforthecomparisonpurposeandonedatasetisanalyzed.

简介：Byutilizingtotalmagneticfluxφoftheprimaryandsecondarywindingsoftheflybacktransformerasastatevariable,thediscrete-timemodelofcurrent-modecontrolledflybackconverterisestablished,uponwhichthebifurcationbehaviorsoftheconverterareanalyzedandtwoboundaryclassificationequationsoftheorbitstateshiftingareobtained.Theoperation-stateregionsofthecurrent-modecontrolledflybackconverterarewellclassifiedbytwoboundaryclassificationequations.Thetheoreticalanalysisresultsareverifiedbypowerelectronicssimulator(PSIM).Theestimationofoperation-stateregionsfortheflybackconverterisusefulforthedesignofcircuitparameters,stabilitycontrolofchaos,andchaos-basedapplications.