最新以全對焦影像合成技術修正失焦顯微鏡影像 Fully Focused-药学医学精品资料.ppt

《最新以全對焦影像合成技術修正失焦顯微鏡影像 Fully Focused-药学医学精品资料.ppt》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、最新以全對焦影像合成技術修正失焦顯微鏡影像FullyFocused-药学医学精品资料OutlineIntroductionOFDMsystemsSignaldistortionmodelOne-tapfrequencydomainRLSequalizerSimulation-Theconvergencebehavioroftheequalizercoefficients-Thedistortionofequalizedsignal-TheMeanSquareErrorofequalizedsignal-Applyone-tapRLSequalizertoOFDMsyst

2、emsConclusion&Futureworks2Motivation在OFDM系統中，一般都把CFO(carrierfrequencyoffset)與SFO(samplingfrequencyoffset)視為同步的問題，鮮少針對同步不準確時，對baseband的影響加以討論。本論文針對CFO與SFO對baseband所產生的影響，並以OFDM常見的一階頻域等化器一併補償通道與CFO、SFO造成的影響。3：eachsubcarrierfrequencyspacing{312.5kHz}：thecarrierfrequencyerrorbetweentransmitt

3、erandreceiver：transmittersamplingperiod{1/20µs}：receiversamplingperiod：numberofIFFT/FFTpoint{64}：Guardintervallength{16}：OFDMsymbollength(Ns=N+G){80}：OFDMusefulsymbolperiod{3.2µs}：Guardintervalperiod{0.8µs}：timingoffsetofreceivedOFDMsymbolk：k-thsubcarrierl：l-thOFDMsymbol{．}:IEEE802.11apa

4、rameterIntroduction(4)7Introduction(5)Signaldistortionmodel:where8Introduction(5)EachsubcarrierhasdifferentphaserotationduetoSFO&CFO.9One-tapRLSequalizer(1)RecursiveLeastSquare(RLS)algorithm:Onetapλ:forgettingfactor0<λ<1.ξ:estimationerror10One-tapRLSequalizer(2)Xk,lismodulatedbyBPSKorQP

5、SK(i.e.

6、Xk,l

7、=1)Takingexpectationsonbothside:11One-tapRLSequalizer(3)let,andviewtheequationasafirstorderIIRfilterformwhenlislargeenough,couldbewritten1storderIIRfilter12One-tapRLSequalizer(4)Takingz-transform,wecanobtainthetransferfunctionofthefirstorderIIRfilter:Theaveragebehavioroftap-

8、weight:13One-tapRLSequalizer(5)Magnitudefrequencyresponseof,Hk=1,nonoise:14One-tapRLSequalizer(5)Phasefrequencyresponseof,Hk=1,nonoise:15Simulation-Thedistortionofequalizedsignal模擬一個子載波上的RLS等化器係數行為:H=1,nonoise60OFDMSymbols等化器係數會持續不斷的更新16Simulation-Thedistortionofequalizedsignal模擬一個子載波上的R

9、LS等化器係數行為:H=1,nonoise60OFDMSymbolsWienerSolutionRLSSolution17Simulation-ThedistortionofequalizedsignalRLSequalizerUn-equalizedsignalEqualizedsignal模擬一個子載波上的RLS等化器QPSK,SNR=20dB,H=1等化過的訊號分成4個聚落，但有大小及相角的失真18Simulation-Thedistortionofequalizedsignal等化後的信號失真與forgettingfactor有關