简介：Theneedforwide-bandclockanddatarecovery(CDR)circuitsisdiscussed.A2Gbpsto12Gbpscontinuous-rateCDRcircuitemployingamulti-modevoltage-controloscillator(VCO),afrequencydetector,andaphasedetector(FD&PD)isdescribed.Anewautomaticfrequencybandselection(FBS)withoutexternalreferenceclockisproposedtoselecttheappropriatemodeandalsosolvetheinstabilityproblemwhenthecircuitispoweringon.Themulti-modeVCOandFD/PDcircuitswhichcanoperateatfull-rateandhalf-ratemodesfacilitateCDRwithsixoperationmodes.TheproposedCDRstructurehasbeenmodeledwithMATLABandthesimulatedresultsvalidateitsfeasibility.

简介：Anovelrotationalinvariancetechniqueforblindestimatesofdirectionofarrival(I)OA)andDopplerfrequencywithunknownarraymanifoldduetoarraysensoruncertaintiesisproposed,takingDopplerfrequencydifferencebetweenasuccessivepulsesasrotationalparameter.Theeffectivenessofthenewmethodisconfirmedbycomputersimulation.Comparedwiththeexisting2-DDOA-frequeucyestimatetechniques,thecomputationloadoftheproposedmethodcanbesavedgreatly.

简介：MostoftheblindOrthogonalFrequencyDivisionMultiplexing(OFDM)CarrierFrequencyOffset(CFO)estimatorsnecessitatelargenumberofsamplestoensuretheestimationaccuracy.However,thenumberofsamplescannotbeselectedtoolargebecauseofthecarrieroffsetdrift.Inthisletter,anewclosedformalgorithmforblindOFDMCFOestimationinfrequency-selectivechannelisproposed.Thismethodutilizesthepropagatorobtainedfromdatamatrixandthediagonalloadingtechnique,thusithasbetterperformanceevenonlyusingoneortwoOFDMblocks.Furthermore,therangeoftheCFOestimationwhichcanbehandledisoveralltransmissionspectral.Simulationresultsconfirmitseffectiveness.

简介：BasedontheanalysisofthespuriousintroducedbyphaseaccumulationtruncationwhichwasmadebyNicholas,anewsimplifiedalgorithmforspuriousspectruminthepresenceofphasetruncationispresentedbyusingthemappingmathematicsandnumbertheoreticmethod,itispossibletopreciselyanalyzethespuriouslocationandthespuriousamplitudeintroducedbyphasetruncationinpracticalapplicationsbycomputer.

简介：Tomaximizethethroughputoffrequency-selectivemulticastchannel,theminimum-phaseFiniteImpulseResponse(FIR)precoderdesignisinvestigatedinthispaper.Thisproblemcanbesolvedintwosteps.Firstly,wefocusondesigninganonminimum-phaseFIRprecoderunderthecriterionofmaximizingthethroughput,anddeveloptwoefficientalgorithmsfortheFIRprecoderdesignfromperspectivesoffrequencydomainandtimedomain.Inthesecondstep,basedonthetheoryofspectralfactorization,thenonminimum-phaseFIRprecoderistransformedintothecorrespondingminimum-phaseFIRprecoderbyaclassiciterativealgorithmwithoutaffectingthethroughput.Numericalresultsindicatethattheachievablerateoftheproposeddesignhasremarkableimprovementoverthatofexistingschemes,moreover,thegroupdelayintroducedbytheFIRprecoderisminimized.

简介：这研究调查堵塞的multitone的频率偏移量怎么影响调音的快跳跃频率的二进制频率移动(FFH/BFSK)自我使添加剂白人Gaussian噪音(AWGN)正常化(SNZ)在\O下面的接收装置。FFH/BFSKSNZ接收装置的平均bit-error-rate(BER)表情和有频率的通讯系统multitone抵消为理解模拟更好结果的缘故堵塞的FFH/BFSK传播光谱(SS)的普通BER表情。当堵塞力量是中等的时，有在堵塞的最糟的casemultitone(MTJ)和AWGN下面的差异的FFH/BFSKSNZ接收装置的BER性能受不了multitone堵塞的模拟结果表演是频率偏移量，它被几模拟验证，不同频率偏移量在堵塞的multitone设置了。因此，在堵塞的multitone下面的FFH/BFSKSNZ接收装置能在堵塞的multitone的频率偏移量的帮助下被作斗争。

简介：在这份报纸，分析了是在直角的频率分割的标志同步算法复合(OFDM)系统，并且完成是粗糙、精致的同步算法的硬件电路设计。基于粗糙、精致的同步算法的分析，多路，模块累加器，部门和输出判断，它能显然保存硬件资源费用。电路顺序和设计计划的波浪表格模拟的分析证明建议方法高效地减少系统资源和电源消费。

简介：TheionospherictimedelayisoneofthemainerrorsourcesinC/AcodeGPSnavigationandpositioningapplications.Inthispaper,amethodisproposedforreal-timedual-frequencyionospherictime-delaycorrectingusingaC/AcodeGPSreceiver,andtheprincipleofthecircuitblockdiagramforthismethodisanalyzedwithitsfeasibilitytheoreticallydemonstrated.

简介：Asanimportantapplicationresearchtopicoftheintelligentaviationmulti-station,collaborativedetectingmustovercometheproblemofscoutingmeasurementwithstatusof“fragmentation”,andtheNP-hardnessproblemofmatchingassociationbetweentargetandmeasurementintheprocessofscoutingtodata-link,whichhascomplicatedtechnicalarchitectureofnetworkconstruction.Inthispaper,takingadvantageofcooperationmechanismonsignallevelintheaviationmulti-stationsympatheticnetwork,amethodofobtainingtargettimedifferenceofarrival(TDOA)measurementusingmulti-stationcollaborativedetectingbasedontime-frequencyassociationisproposed.Themethodcannotonlyachievematchingbetweentargetanditsmeasurement,butalsoobtainTDOAmeasurementbyfurtherevolutionarytransactionthroughrefreshingsequentialpulsetimeofarrival(TOA)measurementmatrixformatchingandcorrelating.SimulationresultsshowthattheaccuracyofTDOAmeasurementhassignificantsuperiorityoverTOA,anddetectionprobabilityoffalseTDOAmeasurementintroducedbynoiseandfakemeasurementcanbereducedeffectively.

简介：TheDirectionsofArrivals(DOAs),speedsanddistancesoftargetsareallrequiredforarraysignalprocessing.Basedontheperiodicphaseshiftofcoherentpulsesequencewaveform,anewestimationofmulti-targets'2-Dimentional(2-D)DOAangle,Dopplerfrequencyshiftandrelativetime-delayisproposed.Basedonavirtualsensorarrayconstructedbypulsecumulating,theestimationsofazimuth,elevation,Doppierfrequencyshiftandtime-delaycanbeobtainedsimultaneously,andtheleastnumberofpulsescouldbetwo.Thismethodiscomputationallyefficienteveninheaviernoisedenvironment,andallestimationsareautomaticallypairedincalculationprocesswithnospectrumsearching.Furthermore,thisalgorithmcanbeusedtoanyplanesensorarrayanddealwithmanytargetsatthesametimeonlybyfewsensors.Thetargetsnumberthatcandealwithsimultaneouslyisseveraltimestothesensornumber,whichistheupperlimitfornormalalgorithmssuchasESPRITandMUSIC.Thesecharacteristicswouldbeveryuseful,especially,foraerialsystems.Simulationsdemonstratethecapabilitiesofthismethodefficiently.

简介：Byemployingaradiofrequency(RF)feedbackchain,theself-interferencecanbecanceledefficientlyinco-timeco-frequencyfullduplex(CCFD).However,theevitablesignalcrosstalkwhichiscausedbytheimperfectRFfeedbackchainisolationusuallydamagestheself-interferencecancelation(SIC)performance.Todealwiththisproblem,firstly,weanalyzetheimpactofRFfeedbackchainisolationonSICperformance.ThenadigitalpreprocessingschemewithRFfeedbackchainisproposedinthemultiple-antennaCCFDarchitecture.Usingbothanalyticalandexperimentalmethods,wefindthattheproposedschemeachievesabetterperformanceonSIC.

简介：Aservocontrolsystemispronetolowspeedandunsteadinessduringvery-low-frequencyfollow-up.Adesignmethodoffeedforwardcontrolbasedonintelligentcontrollerisputfoward.Simulationandtestresultsshowthatthemethodhasexcellentcontrolcharacteristicsandstrongrobustness,whichmeetstheservocontrolneedswithvery-lowfrequency.

简介：Adesignoflaser-diodearray(LDA)end-pumpedNd:YVO4laserthatgeneratessimultaneouslywavelengthsof1064nmand1342nmispresented,andbyusingtype-Icriticalphasematching(CPM)ofBiB3O6,593.5nmcontinuous-wave(CW)laserisobtainedwithintracavitysum-frequencymixing.Themaximumlaseroutputpowercanreach3.63Wwiththepumppowerof27.5W.Theoptical-to-opticalconversionefficiencyisupto13.2%,whichisthehighestvalueat593.5nmbytheintracavitysum-frequencyNd:YVO4laseraccordingtothereporteddata.

简介：精力层次，波浪功能和秒顺序非线性的危险性被基于寓言、非寓言的乐队使用一个不对称的模型在GaAs/Al0.2Ga0.8As/Al0.5Ga0.5As不对称的量井(AQW)计算。当在更宽的井在狭窄的量井并且在更高的躺subband边分析现象时，non-parabolicity的影响不能被忽视。在两倍回声(医生)下面调节的数字结果表演，secondorder差别频率产生(DFG)和光校正(或)分别地，在AQW的产生危险性到达2.5019m/V和13.208m/V它比体积GaAs的那些大得多。而且，我们计算AQW的吸收系数并且发现二泵波长对应于最大的吸收，因此适当的泵横梁必须被选择产生兆兆赫(THz)由DFG的放射。

简介：InviewofthelimitationsofaRn-GnmodelinthelowfrequencyrangeandthedefectsofanEn-Inmodelincommonusenow,thispaperbuildsacompleteEn-Inmodelaccordingtothetheoryofrandomharmonic.Theparametersforthelow-noisedesignsuchastheequivalentinputnoisyvoltageEns,theoptimumsourceimpedanceZsoptandtheminimumnoisefigureFmincanbecalculatedaccuratelybyusingthisEn-Inmodelbecauseitconsidersthecoherencebetweenthenoisesourcesfully.Moreover,thispaperpointsoutthatitwillcausethemaximum30%miscalculationwhenneglectingtheeffectsofthecorrelationcoefficient7.Usingtheseries-seriescircuitsasanexample,thispaperdiscussesthemethodsfortheEn-InnoiseanalysisofelectroniccircuitspreliminarilyanddemonstratesitscorrectnessthroughthecomparisonbetweenthesimulatedandmeasuredresultsoftheminimumnoisefigureFminofasinglecurrentseriesnegativefeedbackcircuit.

简介：Toeliminatethealiasingthatappearedduringthemeasurementofmulti-componentsnonstationarysignals,anovelkindofanti-aliasingalgorithmbasedontheshorttimeFouriertransform(STFT)isbroughtforward.Firstthephysicalessenceofaliasingthatoccursisanalyzed;secondtheinterpolationalgorithmmodelissetupbasedontheHammingwindow;thenthefastimplementationofthealgorithmusingtheNewtoniterationmethodisgiven.Usingthenumericalsimulationthefeasibilityofalgorithmisvalidated.Finally,theelectricalcircuitexperimentshowsthepracticalityofthealgorithmintheelectricalengineering.

简介：用毫微秒脉搏，在红外线附近、中间红外线的激光作为泵来源搏动，我们经由四波浪的差别频率混合获得兆兆赫波浪来源。从联合波浪理论，我们详细分析GaSe水晶和碱金属蒸汽的四波浪的混合进程，得到兆兆赫波浪输出力量的分析表达式，并且讨论为完成阶段匹配的条件。由调整泵频率，碱金属蒸汽的第三顺序的非线性的极化是提高回声的。这个节目提供高力量的兆兆赫放射来源的一种新类型。

简介：Inthispaper,thedesignofsignalconstellationsparametersisstudiedforDifferentialUnitarySpace-TimeModulation(DUSTM)basedonthedesigncriterionofmaximizingthediversityproduct.Further,nonintegersearchingmethodforthesignalconstellationparametersdesignisproposedinordertogetbettercodes.ExperimentalresultsshowthatunderthedifferentDopplerspreadanddatatransmissionrate,theproposeddesignperformsbetterthanthepreviousdesignusingintegerparametersinMultipleInputMultipleOutputOrthogonalFrequencyDivisionMultiplexing(MIMO-OFDM)systemoverfrequency-selectivefadingchannels.

简介：Adiode-pumpedacousto-optical(A-O)Q-switchedextra-cavityfrequency-doubledNd:YVO4/KTP(KTiOPO4)greenlaserformedwithasimpleplane-planecavityhasbeendemonstrated.Withtheincidentpumppowerof12.7W,A-OQ-switchedaverageoutputpowerat1064nmwas3.81Wwithadurationof25nsatarepetitionrateof20kHz,extra-cavityfrequencydoublingwithKTPasthenonlinearcrystalyieldedthemaximumoutputpowerof1.92Wat532nm,thecorrespondingopticalconversionefficiencyfrom1064nmto532nmlightis50.4%.Thecontinuous-wave(CW)laserpropertiesofdiodepumpedNd:YVO4crystaloperatingat1064nmhavebeenstudied.Withtheincidentpumppowerof25W,themaximumCWoutputpowerof13.81Wwasobtainedwiththecorrespondingopticalconversionefficiencyof55.24%.

简介：Highspatialfrequencylaserinducedperiodicsurfacestructures(HSFLs)onsiliconsubstratesareoftendevelopedonflatsurfacesatlowfluencesnearablationthresholdof0.1J/cm2,seldomonmicrostructuresormicrogroovesatrelativelyhigherfluencesabove1J/cm^2.ThisworkaimstoenrichthevarietyofHSFLs-containinghierarchicalmicrostructures,byfemtosecondlaser(pulseduration:457fs,wavelength:1045nm,andrepetitionrate:100kHz)inliquids(waterandacetone)atlaserfluenceof1.7J/cm^2.TheperiodofSi-HSFLsintherangeof110–200nmisindependentofthescanningspeeds(0.1,0.5,1and2mm/s),lineintervals(5,15and20μm)ofscanninglinesandscanningdirections(perpendicularorparalleltolightpolarizationdirection).ItisinterestinglyfoundthatbesidesnormalHSFLswhoseorientationsareperpendiculartothedirectionoflightpolarization,bothclockwiseoranticlockwiserandomlytiltedHSFLswithamaximaldeviationangleof50°ascomparedtothoseofnormalHSFLSsarefoundonthemicrostructureswithheightgradients.RamanspectraandSEMcharacterizationjointlyclarifythatsurfacemeltingandnanocapillarywavesplayimportantrolesintheformationofSi-HSFLs.ThefactthatnoHSFLsareproducedbylaserablationinairindicatesthatmoderatemeltingfacilitatedwithultrafastliquidcoolingisbeneficialfortheformationofHSFLsbyLALs.Onthebasisofourfindingsandpreviousreports,asynergisticformationmechanismforHSFLsathighfluencewasproposedanddiscussed,includingthermalmeltingwiththeconcomitanceofultrafastcoolinginliquids,transformationofthemoltenlayersintoripplesandnanotipsbysurfaceplasmonpolaritons(SPP)andsecond-harmonicgeneration(SHG),andmodulationofSi-HSFLsdirectionbybothnanocapillarywavesandthelocalizedelectricfieldcomingfromtheexcitedlargeSiparticles.