简介:ItisnecessaryforanMC-CDMAuplinkreceivertoemployMUD(multiuserdetection)inafrequencyselectivefadingchannel.AfteranalyzingthealgorithmofPIC(parallelinterferencecancellation)MUD,anovelMUDscheme,Soft-PIC(softparallelinterferencecancellation)isproposed.Basedonthereliabilityofeachdetectedusersignalintheformerstage,thisSoft-PICdetectionschemesubstitutesasoftdecisionofthevariablefortheharddecisioninPICscheme.ComparedwiththePICscheme,itcanreconstructtheinterferencesignalsmoreaccuratelyandeliminateMAI(multipleaccessinterference)inamoreefficientway.PICisoneofthemostpracticalschemesinnumerousmultiuserdetectiontechnologies.However,Soft-PICasanimprovedPICschemedeservesfurtherstudy.
简介:PN(Pseudo-Noise)codetrackingisthemostchallengingtaskinaDirectSequenceSpreadCodeDivisionMultiplexAccess(DS-CDMA)forcelluarmobilecommunicationsystems.Inthispaper,thegravityofenergywindows(GEW)trackingloopofthetimeandfrequencyuncertaintyofthereceivedsignalisinvestigated,andtheGEW’sanalyticalresultsinamulti-pathfadingchannelareintroduced.GEWtrackingloopexploitstheinherentmulti-pathdiversityofthechannel,andhasbetterperformancethansingle-pathonewhenworkinginmulti-pathfadingenvironment.
简介:这篇文章多介绍一篇小说搬运人直接顺序code-divisionmultiple-access(MCDS-CDMA)策划基于泛泛地同步(LS)编码,它能完成很高光谱效率。而不是在一个常规MCDS-CDMA计划的单个副载波调整,这个新奇计划介绍非直角的副载波组调整,其干扰在一个副载波组由非直角的间距引起了,能被amulticode减少察觉者。为这系统体系结构并且也的详细分析满足要求的amultiple-input-multiple输出(MIMO)MCDS-CDMA答案在3Gmobile通讯以外,系统被建议。模仿的结果证明这个计划能获得优秀小点错误率(BER)性能,以及非常完成两次光谱效率作为常规MCDS-CDMA系统的。
简介:TwoblindmultiuserdetectionalgorithmsforantennaarrayinCodeDivisionMultipleAccess(CDMA)systemwhichapplythelinearlyconstrainedconditiontotheLeastSquaresConstantModulusAlgorithm(LSCMA)areproposedinthispaper.OneistheLinearlyConstrainedLSCMA(LC-LSCMA),theotheristhePreprocessingLC-LSCMA(PLC-LSCMA).ThetwoalgorithmsarecomparedwiththeconventionalLSCMA.TheresultsshowthatthetwoalgorithmsproposedinthispaperaresuperiortotheconventionalLSCMAandthebestoneisPLC-LSCMA.