正交频分复用通信系统设计及其性能研究样本

资料内容仅供您学习参考，如有不当或者侵权，请联系改正或者删除。正交频分复用通信系统设计及其性能研究年级:学号:姓名:专业:指导老师:二零一五年五月摘要由于OFDM技术出现了近四十年的时间,该技术在移动通信上已经得到快速发展。本论文主要研究OFDM系统的应用,介绍了OFDM技术的基本概念和发展历程,并简要阐述OFDM在无线移动技术中的发展前景。在介绍OFDM原理的同时,比较FDM与OFDM的异同点,认识保护间隔和循环前缀对OFDM的意义,简述OFDM的优势和缺点,了解OFDM的关键技术,研究OFDM频域和时域的波形图,利用加窗技术来提高OFDM的功率谱密度。关键字:正交频分复用;码间干扰;循环前缀;高斯白噪声 AbstractBecauseofOFDMtechnologyemergedaboutfortyyears,ithasdevelopedrapidlyinthefieldofmobilecommunications,ThisthesismainlystudiestheapplicationofOFDMsystem,introducesthebasicconceptsanddevelopmentoftheOFDMtechnology,besides,thethesisalsodescribesthefuturedevelopmentinwirelessmobiletechnology.WhileintroducetheprinciplesofOFDM,comparingthesimilaritiesanddifferencesbetweenFDMandOFDM,understandingthesignificanceofprotectionintervalandcyclicprefixinOFDM,IdescribedtheadvantagesanddisadvantagesofOFDMbriefly,andknownthekeytechnologiesofOFDM,studiedthedomainwaveformfigureOFDMfrequencydomainandtimedomain,byusingthewindowtechnologytoimprovethepowerspectraldensityofOFDM.Keywords:OFDM;ISI;CP;WGN目录TOC\o"1-3"\h\u17069摘要 ①程序如下N=8;%子载波数f=1:N;%子载波频率x=randint(1,N,[03]);%子载波上的数据x1=qammod(x,4);%4-QAM调制t=0:0.001:1-0.001;%符号持续时间w=2*pi*f.'*t;w1=2*pi*(f+0.2).'*t;%频偏是0.2hzy=x1*exp(j*w);%子载波调制plot(t,abs(y));forii=1:N;y1(ii)=sum(y.*exp(-j*w(ii,:)))/length(t);endstem(abs(x1));holdon;stem(abs(y1),'r<');title('频偏为0的子载波解调结果')axis([0903]