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：帮助递归的最少的广场(RLS)的平行干扰取消(照片)算法被建议在直角的频率部门multiplexing(OFDM)由于搬运人频率偏移量(CFO)取消干扰系统。建议算法由二个阶段组成，它是RLS计划和照片计划。RLS计划被选择在第一个阶段在时间领域补偿频率偏移量，并且干扰由剩余频率偏移量导致了被PIC计划在第二个阶段在频率领域取消。位错误率(BER)的结果证明它的性能作为比较标准为取消是柔韧的，尽管频率偏移量是0.45。16QAM星座也被模仿从建议抑制计划观察改进。

简介：Thewirelesssensornetwork(WSN)consistsofsensornodesthatinteractwitheachothertocollectivelymonitorenvironmentalorphysicalconditionsatdifferentlocationsfortheintendedusers.Oneofitspotentialdeploymentsisintheformofsmarthomeandambientassistedliving(SHAAL)tomeasurepatientsorelderlyphysiologicalsignals,controlhomeappliances,andmonitorhome.ThispaperfocusesonthedevelopmentofawirelesssensornodeplatformforSHAALapplicationoverWSNwhichcomplieswiththeIEEE802.15.4standardandoperatesin2.4GHzISM(industrial,scientific,andmedical)band.TheinitialstageofSHAALapplicationdevelopmentisthedesignofthewirelesssensornodenamedTelGmote.ThemainfeaturesofTelGmotecontributingtothegreencommunicationsincludelowpowerconsumption,wearable,flexible,user-friendly,andsmallsizes.Itisthenembeddedwithaself-builtoperatingsystemnamedWiseOStosupportcustomizedoperation.Thenodecanachieveapacketreceptionrate(PRR)above80%foradistanceofupto8m.ThedesignedTelGmoteisalsocomparablewiththeexistingwirelesssensornodesavailableinthemarket.