超寬帶偽混沌跳時多址系統(tǒng)及其性能分析.pdf

1、南京郵電大學碩士學位論文超寬帶偽混沌跳時多址系統(tǒng)及其性能分析姓名：盧燕申請學位級別：碩士專業(yè)：電路與系統(tǒng)指導教師：蔣國平20090301南京郵電大學碩士研究生學位論文AbstractAbstractUltrawidebandwidthimpulseradio(UWBIR)communicationsystemsareparticularlypromisingforshortrangwirelesscommunicationsasthey

2、combinereducedcomplexitywithhighdatarates，lowpowerconsumption，lowerprobabilityofintercept(LPI)andimmunitytomultipathfadingandmultiusercapabilitiesThemultipleaccess(MA)ofUWBisthekeytechnologyThemajorpurposeforinvestigatin

3、gtheMAtechniquesistoresolvehowtomakemorepeoplesharethefinitefrequencyresourcesInmultiusersystem，availablechannelsaredistributedtomoreUSerSinordertogetpowerfulcapacityensuringthatthesystemperformancedoesn’tbecomeworseFort

4、hepurposeofimprovingtheperformanceandcapacityofMAsystems，furtherstudiesalegoingonabouttheMAtechniquesinUWBsystemThepseudo—chaotictimehoppingschemeisproposedbyintroducingthetheoryofchaosintoUWBsystemInthescheme，thetimehop

5、pingchipscontrolledbypseudorandomnoise(PN)code，isaddedintoflametimeSothat，interferenceamongusersisreduced，andbiterrorratesgetlowerInthisdissertation，thebackgroundanddevelopmentofUWBtechnologyarereviewedbrieflyandthebasic

6、principlesofUWBcommunicationsystems，aswellasthechaoticmappingsandsymbolicdynamicsareintroducedThenmultipleaccessschemesforUWBsuchastimehopping、vimpulsepositionmodulation(TH—PPM)，directsequencebi—phasemodulation(DSBPSK)，a

7、ndpseudo—chaotictimehopping(PCTH)areillustratedTheperformancebetweentheTH—PPMschemeandtheDS—BPSKschemearecomparedbysimulationsFurthermoretheperformanceofmultipleaccesssystemforPCTH(MA—PCm)isstudiedThentheproblemofMAPCTHi

8、sanalyzedTothisproblem，anovelschemeisproposedbasedontheMAPCTHcommunicationsystemBiphasemodulation(BPSK)isappliedintheproposedscheme，insteadofpulsepositionmodulation，andtimehoppingcodeisaddedinordertoreduceinterferenceamo

9、ngusersTheimprovedsystemhassomedesiredfeatures，suchaslowbiterrorrate，lowprobabilityofintercept，andlowprobabilityofcollisionbetweenusersAnalysisandsimulationresultsshowthatthemodifiedsystemhasbetterperformancethanPCTHinAW