预览加载中,请您耐心等待几秒...
1/2
2/2

在线预览结束,喜欢就下载吧,查找使用更方便

如果您无法下载资料,请参考说明:

1、部分资料下载需要金币,请确保您的账户上有足够的金币

2、已购买过的文档,再次下载不重复扣费

3、资料包下载后请先用软件解压,在使用对应软件打开

MB-OFDM系统中的信道估计与均衡技术研究的中期报告 Introduction MB-OFDM(MultibandOrthogonalFrequencyDivisionMultiplexing)isapopularwirelesscommunicationsystemthatutilizesmultiplefrequencybandsfortransmissiontoimprovethedatarateandreliabilityofcommunication.MB-OFDMhasfoundapplicationsinvariousfieldssuchasWiMedia-basedWirelessPersonalAreaNetwork(WPAN),Ultra-Wideband(UWB)technologyforhigh-speeddatatransferandwirelessUSBtechnology. TheperformanceofMB-OFDMsystemishighlydependentonthequalityofthechannelestimationandequalizationtechniques.Inthisreport,wewilldiscussthecurrentresearchonchannelestimationandequalizationtechniquesforMB-OFDMsystemsandtheireffectivenessinimprovingthesystemperformance. ChannelEstimationTechniques Likeanywirelesscommunicationsystem,theperformanceofMB-OFDMsystemishighlydependentontheaccuracyofthechannelstateinformation(CSI).ChannelestimationistheprocessofestimatingtheCSIatthereceiverbasedonthereceivedsignal.InMB-OFDMsystems,channelestimationisachallengingtaskduetothepresenceofmulti-pathfading,inter-carrierinterference(ICI)andnoise. AlotofresearchhasbeendoneintheareaofchannelestimationtechniquesforMB-OFDMsystems.Amongthem,twopopulartechniquesarepilot-basedchannelestimationandblindchannelestimation. Pilot-basedchannelestimationusesdedicatedpilotsubcarriersinthefrequencydomainfortransmittingknownpilotsymbols.Thereceiverusesthesepilotsymbolstoestimatethechannelresponseandtheninterpolatestheestimatedchannelresponseforthedatasubcarriers.Thistechniqueissimpleandefficient,butitsuffersfromtheoverheadofpilotsymbols,whichreducestheavailabledatarate. Blindchannelestimation,ontheotherhand,doesnotrequireanypilotsymbols,anditestimatesthechannelresponsepurelybasedonthereceivedsignal.Blindchannelestimationalgorithmsusestatisticalmethods,suchasMinimumMeanSquareError(MMSE)andLinearMinimumMeanSquareError(LMMSE),toestimatethechannelresponse.Blindchannelestimationtechniqueshavetheadvantageofnotrequiringanypilotsymbols,buttheyarecomputationallymoreintensivethanpilot-basedtechniques. Equalizatio