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1、论文实例:低/零相关区理论与扩频通信系统序列设计简介:唐小虎,男,1972年03月出生,1998年09月师从于西南交通大学范平志教授,于2001年06月获博士学位。摘要理想情况下,CDMA通信系统中使用的扩频序列集应具有如下相关特性:1.每个扩频序列的自相关函数应该是一个冲激函数,即除零时延外,其值应处处为零;2.每对扩频序列的互相关函数值应该处处为零。遗憾的是,已经证明具有这种理想相关特性的序列集是不存在的。近年来低/零相关区扩频序列的研究引起了广泛关注,它针对准同步CDMA系统的特性,即系统的同步误差控制在一定范围之内,如一个或几个码片周期,
2、要求扩频序列在同步误差范围内具有(接近)理想相关特性。本论文围绕低/零相关区理论,对低/零相关区扩频序列的理论界、低相关区扩频序列设计、具有低/零相关区的二维信号设计、整环上正交序列集设计、LA序列设计等五个方面内容进行了深入研究。针对一些相关函数(包括非周期相关函数、周期相关函数、周期奇相关函数)具有低/零相关区特性的序列,在A扩频通信系统,降低甚至消除共信道干扰,提高系统容量。关键词:扩频序列,准同步CDMA系统,低相关区,零相关区THETHEORYOFLOMUNICATIONSYSTEMAtractIdealcodesusedforCDMA
3、systemshouldhaveimpulsive-likeauto-correlationfunctioandzerocro-correlationfunctio.Unfortunately,ithasbeenshooreandmoreattention.Thesesequenceshaveidealorverylo,onguserscanbecontrollediibletimedifference.Inthisthesis,fivesequencedesigntopicsrelatedtothetheoryofloworzerocorrel
4、ationzone(LCZorZCZ)areinvestigated,i.e.,lowerboundsonthecorrelationofthereadingsequencesetwithloworzerocorrelationzone,sequencedesignwithlowcorrelationzone,binaryarraydesignwithloworzerocorrelationzone,orthogonalreadingsequencedesignover,andtheLAsequencedesign.Basedonthebound
5、sonierproduct,wehaveestablishedseveralboundsonvariouscorrelatioofLCZ(ZCZ)sequences,includeaperiodiccorrelationbound,periodiccorrelationboundandoddcorrelationbound.Ourinvestigatonshowsthat,al12全文查看lknoboundsonierproduct,canbeextendedtoLCZorZCZsequencesbylimitingthecorrelationo
6、perationrangeore,thecorrelationvaluesarealmostallequalto-1edurationexceptforafeplerforapairofm-sequences,alargeclaofasymptoticallyoptimalpolyphaseLCZsequenceset,canbeobtained.Inaddition,byborroptoticallyoptimalbinaryLCZsequencessetispresented.BygeneralizingtheconceptofZCZandL
7、CZfromone-dimeiontoteion,aclaofbinaryarraysutuallyorthogonalteionalplementarycodes,ispresented.Besides,aclaofbinaryarraysilarconceptandcotructioncabeeasilyextendedtothree-dimeionalorhigherdimeionalcode-sequenceoverGF(p),amethodforcotructingorthogonalsequencesetsoverGaloisring
8、isderivedbymakinguseofthetracefunction.Itcanbesimplyrealizedbymeaoft