简介：Thispaperpointsoutthatsynchronizationofhyperchaosmaybeachievedbyanonlinearfeedbackwithoutdecomposingtheoriginalsystem.ItappliestheideastoRosslersystem,anddiscussesseveralformsofnonlinearfeedbachbyLyapunovfunctionandnumericalcalculation.

简介：Athresholdsettingschemeisproposedbasedontheresourcemanagementandlimitedfeedbacktheoryinmultiuserorthogonalfrequencydivisionmultiplexing(OFDM)systems.Inadaptiveresourceallocation,thefactorsdenotingthequalityofservice(QoS)andfairnessarebothconsideredastheuserweight.Fromtheaspectoffeedbackoutageprobability,theproposedalgorithmsetsthethresholdforeachuserrelatedtoitsweight,whichbringsenoughfeedbacktotheuserwithgreaterweight.Analysisandsimulationresultsshowthat,comparedwiththethresholdignoringweights,theproposedschemehasmuchlowerfeedbackloadwhilewithbetterQoS.

简介：Inthispaper,thefeedbackloadreductionprobleminwirelesssystemsbasedonorthogonalfrequencydivisionmultiplexing(OFDM)isinvestigatedandanopportunisticfeedbackscheme(OFS)isproposed.ThekeyideabehindOFSisthatonlythekeychannelgainswhichcansignificantlyaffectthesystemthroughputarefedbacktotheBS.Firstly,thekeychannelgainsareprovedtobelongtoachannelgaininterval.Secondly,astatisticalmethodisproposedtoestimatethechannelgaininterval.Thirdly,theopportunisticfeedbackschemeisformulatedandthefeedbackloadofOFSisanalyzed.TheadvantageofOFSisthreefold:thefirstisOFScanworkinbothOFDM-basedmulticastsystemandOFDM-basedunicastsystem.ThesecondisthechannelfadingtypeoftheBS-userlinkisnotrequired,whichismorerealistic.ThethirdisOFScangetbetterfeedbackloadperformancecomparedwithotherschemes,whileachievingalmostthesamethroughputperformancecomparedwiththatoffullfeedbackscheme.

简介：Bydeducingthedistributionofthenormalizedchannelcovariancematrix,anovellimitedfeedbackschemeisproposedundermultipleusers(MU)multiple-inputmultiple-output(MIMO)broadcastchannel(BC)system.Theproposedschemehasadvantagesinthreeaspects.First,ithasnoconstraintsonthenumberofusersorantennas.Second,eachuser'sfeedbackbitsareindependentofthenumberofreceivingantennas.Third,theproposedschemeavoidsthestorageoflarge-sizecodebookonthetransceivers.Simulationresultsshowthattheperformanceoftheproposedschemeisclosetotheperfectchannelstateinformation(CSI)caseanditjustneedsasmallnumberoffeedbackbits.

简介：Themainchallengesofdatastreamsclassificationincludeinfinitelength,concept-drifting,arrivalofnovelclassesandlackoflabeledinstances.Mostexistingtechniquesaddressonlysomeofthemandignoreothers.Soanensembleclassificationmodelbasedondecision-feedback(ECM-BDF)ispresentedinthispapertoaddressallthesechallenges.Firstly,adatastreamisdividedintosequentialchunksandaclassificationmodelistrainedfromeachlabeleddatachunk.Toaddresstheinfinitelengthandconcept-driftingproblem,afixednumberofsuchmodelsconstituteanensemblemodelEandsubsequentlabeledchunksareusedtoupdateE.Todealwiththeappearanceofnovelclassesandlimitedlabeledinstancesproblem,themodelincorporatesanovelclassdetectionmechanismtodetectthearrivalofanovelclasswithouttrainingEwithlabeledinstancesofthatclass.Meanwhile,unsupervisedmodelsaretrainedfromunlabeledinstancestoprovideusefulconstraintsforE.AnextendedensemblemodelExcanbeacquiredwiththeconstraintsasfeedbackinformation,andthenunlabeledinstancescanbeclassifiedmoreaccuratelybysatisfyingthemaximumconsensusofEx.ExperimentalresultsdemonstratethattheproposedECM-BDFoutperformstraditionaltechniquesinclassifyingdatastreamswithlimitedlabeleddata.

简介：在这份报纸，一个频率领域决定反馈均衡器为单身的搬运人传播被建议，时间颠倒时空块(TR-STBC)编码。斜决定反馈均衡器矩阵能从频率领域隧道反应是计算的，这被显示出。在完美的反馈假设下面，建议均衡器能接近匹配的过滤器界限(MFB)。与存在时间领域决定反馈均衡器相比，建议均衡器与一样的均等复杂性展出更好的性能。

简介：Thepapermainlystudiesthesum-rateperformanceoflimitedfeedback(LFB)block-diagonalization(BD)inmulti-userdistributedantennasystem(DAS).Asthechannelstateinformation(CSI)fedbacktobasestation(BS)islimited,multi-userinterference(MUI)iscausedinevitablybecauseofthequantizationerror.ConsideringtheinfluenceoftheMUItothecapacityofDAS,weproposeaparameterofeffectivesum-rateratio(ESRR)todenotethecapacityoffsetundertheconditionoftheBScangetperfectCSIandlimitedCSIfirst,thenweconfirmthattheapproximatedESRRisveryclosetoactualESRRgotthroughsimulations.Afterthat,basedontheapproximatedESRR,anadaptiveminimumbitfeedbackschemewhichcaneffectivelyreducetheoverheadoffeedbackchannelandthecomplexityofthesystemisproposed.Simulationresultsshowtheeffectivenessoftheproposedscheme.