基于LDPC碼的IDMA通信系統(tǒng)性能研究.pdf

1、分類號TN9145密級重慶郵電大學碩士學位論文論文題目基于LDPC碼的IDMA通信系統(tǒng)性能研究英文題目PerformanceofLDPCCodedIDMASystem碩士研究生矍堯指導教師王鹽熬撞學科專業(yè)通信與信息系統(tǒng)論文提交日期—2007—430論文答辯日期—2007—66論文評閱八到光遠教授西南盤掌陶疊熬撞重慶酆蟲盤堂答辯委員會主席陶洋教授重慶郵電大學2007年4月20日重慶郵電大學碩士論文AbstractInrecentyears

2、，IDMAasthekeytechnologyin4“mobilecommunicationhasbeenwildlystudiedIDMAnotonlyinheritsmanyadvantagesfromCDMA，especiallydiversityagainstfading，butalsohassomeownadvantages，suchasasimpleChipbyChipiterativereceiverstructure，h

3、ighspectralefficiencyandexcellentperformanceofmultiuseraccessFormakingitclosertothemultipleaccesschannel(MAC)capacitylimits，LDPCcodesisappliedtoIDMAsystem，andLDPCCodedIDMAsystemispresentedinthispaperThoughcomputersimulat

4、ion，theperformanceofthedesignedsystemhasbeeninvestigatedandanalyzeddeeplyFurthermore，theoptimalLDPCcoderatesofthedesignedsystemhavebeenfoundandLDPC—CodedIDMAsystemiscomparedwithIDMAsystembasedonconvolutionalcodesgenerall

5、yindifferentconditionsSimulationresuItsindicatethatLDPCCodedIDMAsystemnotonlyinheritsmanyadvantagesfromIDMAsystem，butalsohasitsownpredominance，suchasclosertomultipleaccesschannel(MAC)capacitylimits，obtainsmorecodinggains

6、，andsupplieshigherqualitycommunicationserviceFurthermore，themiddleLDPCcoderatesarethebestchoiceforthissystemOverAWGNchannel，performanceofthedesignedsystemwith16usersisabout26dBawayfromtheMACcapacitylimitsatbiterrorrateof

7、10一，and34dBbetterthanthesystembasedonconvolutionalcodes；theoptimalLDPCcoderatesarebetween04and05InfastRayleighfadingchannel，eventhecodinglengthofthedesignedsystemisjust512bits，itstillhas3dBcodinggainsoverthetraditionalco

8、dedsystematbiterrorrateOf10～TheresultsshowthatthedesignedsystemisverysuitableforhighspeedtransmissionoperationandthisworkisofthefarreachingsignificanceinfuturedigitalcommunicationsystemKeywords：InterleaveDivisionMultiple