简介:ExistingEthernetPassiveOpticalNetwork(EPON)DynamicBandwidthAllocation(DBA)algorithmssufferfromthedisadvantageofidletimeloss,whichlowertheupstreambandwidthutili-zation.Thisletterproposesanimprovedupstreamtransmissionschemewithidle-timeeliminatingmechanism.Theoreticalanalysisandnumericalcalculationprovethattheimprovedschemecanef-fectivelyeliminatetheidletimeandenhancetheefficiencyofupstreamlinkutilization.Simulationresultshaveshownthatthebandwidthutilizationcanberaisedupto15%inheavy-loadscenarioswhilethetimedelayperformanceofAssuredForwarding(AF)andBestEffort(BE)servicesareimprovedsimultaneously.
简介:IntheH.263videocodecrelatedsystems,motionestimationandDiscreteCosineTransform(DCT)havethemostcomputationalrequirements.Inordertoreducecomplexityoftheencodertodedicatemoreresourcestootherfunctions,accordingtothestudyofexistingmethods,anImprovedAllZeroBlockFinding(IAZBF)methodbasedonthestatisticcharacteristicsofDCTcoefficientsisproposed.Comparedwithexistingmethods,IAZBFimprovesthedetectingefficiencybyabout50%withoutimportingtoomuchextracomputationrequirement.Beingcomputedwithadditionsandshiftsinsteadofcomplicatedmultiplications,IAZBFisoflowcomputationcomplexity,especiallyforlow-endprocessors.Inaddition,IAZBFupholdspicturefidelityandremainscompatiblewiththeH.263bitstreamstandard.
简介:ThispaperpresentsanRFreceiverofzero-IntermediateFrequency(IF)architectureforCognitiveRadio(CR)communicationsystems.Zero-IFarchitecturereducetheimagerejectfilterandIFfilter,soitisexcellentinlowcost,compactvolume,andlowpowerdissipation.Thereceiveremploysthreedigitalattenuatorandahighgain,highlinearitylownoiseamplifiertoachievewidedynamicrangeof70dBandhighreceivingsensitivityof-81dBm.AfullybalancedI/QdemodulatorandadifferentialLocalOscillator(LO)chipsareusedtominimizethenegativeeffectscausedbysecond-orderdistortionandLOleakage.Inordertoselectan8MHz-channelfrom14continuousoneslocatedinUHFband(694-806MHz)accurately,approachofchannelselectivitycircuitsisproposed.TheRFreceiverhasbeendesigned,fabricated,andtest.Themeasuredresultshowsthatthenoisefigureis3.4dB,andtheerrorvectormagnitudeis7.5%whentheinputpoweris-81dBm.
简介:Thezero-voltagequasi-resonantboostswitchingDC-DCconverterhasbeeninves-tigatedbyusingthetimeaveragingequivalentcircuitapproachofperiodicallyswitchinglinearnetworks.TheDCsteadystateandACsmallsignalcharacteristicsoftheconverterarealsogiven.
简介:Aservocontrolsystemispronetolowspeedandunsteadinessduringvery-low-frequencyfollow-up.Adesignmethodoffeedforwardcontrolbasedonintelligentcontrollerisputfoward.Simulationandtestresultsshowthatthemethodhasexcellentcontrolcharacteristicsandstrongrobustness,whichmeetstheservocontrolneedswithvery-lowfrequency.
简介:Becauseofthezerodispersionwavelength(ZDWL)randomfluctuations,thegainandnoisefiguresdeteriorateinopticalparametricamplifiersbasedonhighlynonlinearfibers(HNLFs).ThedetrimentalroleofZDWLfluctuationsonthegainandnoiseperformanceindual-pumpfiberopticalparametricamplifiers(FOPAs)ispresented.Numericalinvestigationsofnoisefigure(NF)fordifferentfiberswithrandomfluctuationareanalyzed.Thenoisefiguresfordifferentfibersarevaryingeveniftherandomfluctuationissmall.ThroughchoosingHNLFswithlowZDWLfluctuationandlargenonlinearcoefficient,high-gainandlow-noiseperformancecanbeobtained.
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:Anon-intrusivedesignformonitoringeverydayactivitiesofanelderlypersonispresented.Theproposedsystemisintendedtobeusedinthebedroom,allowingtheelderstostayathomeinasafeenvironment.Therequiredhardwaredesignissimpleinstructureandcosteffective.ThesensordesignisimplementedbyusingcapacitivesensorsandanArduinomicrocontrollerunit.Andarealtimegraphicaluserinterfaceisimplementedtomonitortheelderlyperson.Theperformanceanalysisshowsthatthesensordesignisabletodifferentiatebetweenahumanbodyandahousepet.
简介:Thefeaturesofnon-voicesignalsonpubliccommunicationnetsareanalyzedandanapproachtodistinguishsuchsignalsisintroducedinthispaper.Itisthefirsttimeforthesystemtomeetthreekeytargets:large-scale,highrecognitionrateandlowfalsealarmatthesametime.
简介:Assemblingindividuallinephasefilterstoformamulti-channelfilterbankallowsthesynthesisfiltertobesimilartocorrespondinganalysisfilters,andthedesigncalculationcanbesimple.Theappropriaterelationsbetweensynthesisfiltersandanalysisfilterseliminatemostaliasingresultingfromdecimationinnon-uniformmaximallydecimatingfilterbanks,andLSalgorithmandRemezalgorithmareusedtooptimizethecompositecharacter.ThisdesignmethodcanachieveapproximatePerfect-Reconstruction.Anexampleisgiveninwhichthegeneralparameterfilterswithapproximatelinephaseareusedasunitsofafilterbank.
简介:Thecharacteristicsoflow-frequencyelectricalnoise,voltage-current(V-I)andelectricalderivationfor980nmInGaAsP/InGaAs/GaAshighpowerdoublequantumwelllasers(DQWLs)aremeasuredunderdifferentconditions.Thecorrelationofthelow-frequencyelectricalnoisewithsurfacenon-radiativecurrentofdevicesisdiscussed.Theresultsindicatethelow-frequencyelectricalnoiseof980nmDQWLswithhighpowerismainly1/fnoiseandhasgoodrelationwiththedevicesurfacecurrentatlowinjection.
简介:适应调整并且(AMC)编码提供灵活性匹配调整和编码计划(MCS)加用户的噪音比率(SINR)发信号到干扰。为了减少传播,驱动并且维持传播质量,力量控制通常与AMC被相结合。当力量控制的目标SINR被修理时,为AMC(NPGA)算法的因此非合作的力量控制游戏被建议根据MCS适应动态目标SINR变化。在NPGA,我们经由用途提出系统传播效率,在实用程序函数基于调整被构造并且与非合作的游戏理论编码效率的地方。NPGA能满足supermodular比赛的条件,这理论上被表明,并且它的答案是最佳的。模拟结果证明NPGA能与低传播力量,和NPGA的集中性能改进系统传播效率和信号质量与几何编程算法相比是更快有效性的。
简介:Byaccuratelymeasuringthedisplacementbetweentherollersurfaceandtheopticalfiberproberelativetoanullposition,wecantesttherollerwear.Thewholetestingmethodandsystemwereintroduced.Eachpartofthetestingsystemwasillustrated.Andalsoanovelfiber-opticsensorwiththreeprobesinequaltransversespaceisadopted.Usingthissensor,theeffectsoffluctuationsinthelightsource,reflectivitychangingoftargetsurfaceandtheintensitylossesinthefiberlinesareautomaticallycompensated.Thismethodofferssuchadvantagesasnon-contact,noelectromagneticinterference,simplicity,lowcost,highsensitivity,goodaccuracyandstability.
简介:EnergyisthedeterminantfactorforthesurvivalofMobileSensorNetworks(MSN).Basedontheanalysisoftheenergydistributioninthispaper,atwo-phaserelocationalgorithmisproposedbasedonthebalancebetweentheenergyprovisionandenergyconsumptiondistribution.Ourmainobjectivesaretomaximizethecoveragepercentageandtominimizethetotaldistanceofnodemovements.Thisalgorithmisdesignedtomeettherequirementofnon-uniformdistributionnetworkapplications,toextendthelifetimeofMSNandtosimplifythedesignoftheroutingprotocol.Inad-dition,testresultsshowthefeasibilityofourproposedrelocationalgorithm.
简介:声音变换(VC)基于Gaussian混合模型(GMM)是变换来源光谱指向光谱的最经典、普通的方法。然而,这个方法对敏感因为它的frame-by-frame变换在恰当上。有非否定的矩阵因式分解(NMF)的VC在这份报纸被介绍,它能阻止光谱由调整基础向量(字典)的尺寸在恰当上。以便认识到更好的非线性的印射,核NMF(KNMF)被采用完成印射的光谱。另外,增加变换的精确性,与GMM(GKNMF)相结合的KNMF也被介绍进VC。最后,KNMF,GKNMF,GMM,主要部件回归(PCR),与GMM(GPCR)相结合的PCR,部分最不方形的回归(PLSR),变弯的NMF基于关联的频率(NMF-CFW)和深神经的网络(DNN)方法与对方相比。建议GKNMF在客观评估和主观评估得到更好的性能。
简介:Lowpowerconsumptionisamajorissueinnowadayselectronicssystems.ThistrendispushedbythedevelopmentofdatacenterrelatedtocloudservicesandsoontotheInternetofThings(IoT)deployment.Memoriesareoneofthemajorcontributorstopowerconsumption.However,thedevelopmentofemergingmemorytechnologiespavesthewaytolow-powerdesign,throughthepartialreplacementofthedynamicrandomaccessmemory(DRAM)withthenon-volatilestand-alonememoryinserversorwiththeembeddedordistributedemergingnon-volatilememoryinIoTobjects.Inthelattercase,non-volatileflip-flops(NVFFs)seemapromisingcandidatetoreplacetheretentionlatch.Indeed,IoTobjectspresentlongsleeptimeandNVFFsoffertosavedatainregisterswithzeropowerwhentheapplicationisidle.ThispapergivesanoverviewofNVFFarchitectureflavorsforvariousemergingmemorytechnologies.
简介:Amodifiednon-coherentsequentialdetectiondecisionlogicbasedoncontinuousaccumulationtoachievefastPNcodeacquisitionisproposed.Tosimplifythedesignandanalysis,theequivalentrelationshipbetweenthelikelihoodratioofthecurrentsampleandthatofalltheprevioussamplesisdeduced.Theschemeisprovedtobeanoptimumsequentialdetectionundercertainassumptions.Becausetheaveragesamplenumber(ASN)cannotbecalculatedthroughthemethodsappliedtotheconventionalsequentialdetection,analgorithmisalsoprovided,whichcanestimateboththeprobabilitydensityfunction(pdf)andtheupperthresholeofASN.Thedesiredprobabilitiesoffalsealarmanddetection,aswellasfasterPNcodeacquisitioncomparedtotheconventionalsequentialdetectioncanbeachievedbyemployingthisstructure.Inaddition,Rayeigh-fadedreceptioncaseisalsotakenintoconsideration.Performancesoftheproposedschemesareobtained,whichsuggestthattheproposednon-coherentsequentialdetectionismoredesirable.
简介:Traditionaldigitalprocessingapproachesarebasedonsemiconductortransistors,whichsufferfromhighpowerconsumption,aggravatingwithtechnologynodescaling.Tosolvedefinitivelythisproblem,anumberofemergingnon-volatilenanodevicesareunderintenseinvestigations.Meanwhile,novelcomputingcircuitsareinventedtodigthefullpotentialofthenanodevices.Thecombinationofnon-volatilenanodeviceswithsuitablecomputingparadigmshavemanymeritscomparedwiththecomplementarymetal-oxide-semiconductortransistor(CMOS)technologybasedstructures,suchaszerostandbypower,ultra-highdensity,non-volatility,andacceptableaccessspeed.Inthispaper,weoverviewandcomparethecomputingparadigmsbasedontheemergingnanodevicestowardsultra-lowdissipation.