正交頻分復用通信系統(tǒng)設計及其性能研究樣本

資料內容僅供您學習參考，如有不當或者侵權，請聯(lián)系改正或者刪除。正交頻分復用通信系統(tǒng)設計及其性能研究年級:學號:姓名:專業(yè):指導老師:二零一五年五月摘要由于OFDM技術出現(xiàn)了近四十年的時間,該技術在移動通信上已經得到快速發(fā)展。本論文主要研究OFDM系統(tǒng)的應用,介紹了OFDM技術的基本概念和發(fā)展歷程,并簡要闡述OFDM在無線移動技術中的發(fā)展前景。在介紹OFDM原理的同時,比較FDM與OFDM的異同點,認識保護間隔和循環(huán)前綴對OFDM的意義,簡述OFDM的優(yōu)勢和缺點,了解OFDM的關鍵技術,研究OFDM頻域和時域的波形圖,利用加窗技術來提高OFDM的功率譜密度。關鍵字:正交頻分復用;碼間干擾;循環(huán)前綴;高斯白噪聲 AbstractBecauseofOFDMtechnologyemergedaboutfortyyears,ithasdevelopedrapidlyinthefieldofmobilecommunications,ThisthesismainlystudiestheapplicationofOFDMsystem,introducesthebasicconceptsanddevelopmentoftheOFDMtechnology,besides,thethesisalsodescribesthefuturedevelopmentinwirelessmobiletechnology.WhileintroducetheprinciplesofOFDM,comparingthesimilaritiesanddifferencesbetweenFDMandOFDM,understandingthesignificanceofprotectionintervalandcyclicprefixinOFDM,IdescribedtheadvantagesanddisadvantagesofOFDMbriefly,andknownthekeytechnologiesofOFDM,studiedthedomainwaveformfigureOFDMfrequencydomainandtimedomain,byusingthewindowtechnologytoimprovethepowerspectraldensityofOFDM.Keywords:OFDM;ISI;CP;WGN目錄TOC\o"1-3"\h\u17069摘要 ①程序如下N=8;%子載波數(shù)f=1:N;%子載波頻率x=randint(1,N,[03]);%子載波上的數(shù)據(jù)x1=qammod(x,4);%4-QAM調制t=0:0.001:1-0.001;%符號持續(xù)時間w=2*pi*f.'*t;w1=2*pi*(f+0.2).'*t;%頻偏是0.2hzy=x1*exp(j*w);%子載波調制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('頻偏為0的子載波解調結果')axis([0903]