简介：AnalgorithmbasedoneigenanalysistechniqueandWalsh-Hadamardtransform(WHT)isproposed.Thealgorithmcontainstwosteps.Firstly,thereceivedsequenceisdividedintotemporalwindows,andacovariancematrixiscomputed.Thelinearfeedbackshiftregister(LFSR)sequenceisreconstructedfromthefirsteigenvectorofthismatrix.Secondly,equationsaccordingtotherecoveredLFSRsequenceareconstructed,andtheWalshspectrumcorrespondingtotheequationsiscomputed.ThefeedbackpolynomialofLFSRisestimatedfromtheWalshspectrum.Thevalidityofthealgorithmisverifiedbythesimulationresult.Finally,casestudiesarepresentedtoillustratetheperformanceoftheblindreconstructionmethod.

简介：Awayofresolvingspreadingcodemismatchesinblindmultiuserdetectionwithaparticleswarmoptimization(PSO)approachisproposed.IthasbeenshownthatthePSOalgorithmincorporatingthelinearsystemofthedecorrelatingdetector,whichistermedasdecorrelatingPSO(DPSO),cansignificantlyimprovethebiterrorrate(BER)andthesystemcapacity.Asthecodemismatchoccurs,theoutputBERperformanceisvulnerabletodegradationforDPSO.Withablinddecorrelatingscheme,theproposedblindDPSO(BDPSO)offersmorerobustcapabilitiesoverexistingDPSOundercodemismatchscenarios.