基于某Matlab地ASK仿真

基于MATLAB的2ASK調(diào)制根據(jù)數(shù)字帶通調(diào)制原理，運(yùn)用 進(jìn)行編程，仿真調(diào)制過程，記錄并分析仿真結(jié)果。形成設(shè)計(jì)報(bào)告。課程設(shè)計(jì)需要運(yùn)用MATLAB編程實(shí)現(xiàn)2ASK,2FSK,2PSK，2DPSK調(diào)制解調(diào)過程，并且輸出其調(diào)制后的波形，畫出頻譜、功率譜密度圖，并比較各種調(diào)制的誤碼率情況，討論其調(diào)制效果。二進(jìn)制數(shù)字調(diào)制技術(shù)原理數(shù)字信號(hào)的傳輸方式分為基帶傳輸和帶通傳輸，在實(shí)際應(yīng)用中，大多數(shù)信道具有帶通特性而不能直接傳輸基帶信號(hào)。為了使數(shù)字信號(hào)在帶通信道中傳輸，必須使用數(shù)字基帶信號(hào)對(duì)載波進(jìn)行調(diào)制，以使信號(hào)與信道的特性相匹配。這種用數(shù)字基帶信號(hào)控制載波，把數(shù)字基帶信號(hào)變換為數(shù)字帶通信號(hào)的過程稱為數(shù)字調(diào)制。通常使用鍵控法來實(shí)現(xiàn)數(shù)字調(diào)制，比如對(duì)載波的振幅、頻率和相位進(jìn)行鍵控。2ASK2ASK信號(hào)的產(chǎn)生方法通常有兩種：模擬調(diào)制和鍵控法。解調(diào)有相干解調(diào)和非相干解調(diào)。P=1時(shí)f(t)=Acoswt;p=0時(shí)f(t)=0;其功率譜密度是基帶信號(hào)功率譜的線性搬移

2.2數(shù)字調(diào)制技術(shù)的仿真實(shí)現(xiàn)2.2數(shù)字調(diào)制技術(shù)的仿真實(shí)現(xiàn)是一種功能強(qiáng)大的科學(xué)計(jì)算和工程仿真軟件，它的交互式集成界面能夠幫助用戶快速的完成數(shù)值分析、數(shù)字信號(hào)處理、仿真建模、和優(yōu)化等功能。本課程設(shè)計(jì)需要運(yùn)用編程實(shí)現(xiàn)，調(diào)制解調(diào)過程，并且輸出其調(diào)制后的波形，畫出頻譜、功率譜密度圖，并比較各種調(diào)制的誤碼率情況，討論其調(diào)制效果。3?程序與調(diào)試圖形3.1、ASK調(diào)制解調(diào)3.1?1ASK程序：3.32ASK圖形：closeallclearalln=16;fc=1000000;%fc>=bitRatefc/bitRate為每個(gè)二進(jìn)制包含sin周期個(gè)數(shù)bitRate=1000000;N=50;%noise=ti;noise=10;

signal=source(n,N);transmittedSignal=askModu(signal,bitRate,fc,N);signall=gussian(transmittedSignal,noise);configueSignal=demoASK(signall,bitRate,fc,n,N);4.集4.集聲后信號(hào)］II}Figure2lnlx|FileEditViewInsertToolsDesktopWindowHelp□ QBfe題Qf??IflI□ni□□ModulationofASKDi~~K0.80.60.40.2-0.2-04-0.6-0.83.信道加噪-1

Figure6_ln|x|Eile脫itYiewInsertloolsDesktopitindowHelpTOC\o"1-5"\h\z□hafe愆q脅?運(yùn)□□ □Waveofreceivingterminal(includingnoise)5 ^ ^I I I Illi0I I I Illi-50 100 200 300 400 500 600 700 8005.解調(diào)出的 5.解調(diào)出的 一"亍、一0 __ r r r 7 t t t 3?4、誤碼率分析1.ASK誤碼率分析IFigwe2|n|x|||ZileEdithewInzertToolslesktopWindowHelp□QS1運(yùn)1口□1□□ASKclearallclosealli=10;j=5000;t=linspace(0,5,j);%取0,0.001,0.002,。。。5共5001個(gè)點(diǎn)fc=10;fm=i/5;B=2*fc;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%產(chǎn)生基帶信號(hào)a=round(rand(1,i));%隨機(jī)序列figure(2)plot(rand(l,i))st=t;forn=l:10ifa(n)<1;form=j/i*(n-l)+l:j/i*n %—個(gè)信號(hào)取500個(gè)點(diǎn)st(m)=0;endelseform=j/i*(n-1)+1:j/i*nst(m)=1;endendendfigure(l);subplot(421);plot(t,st);axis([0,5,-l,2]);title('基帶信號(hào)')；%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%載波sl=cos(2*pi*fc*t);subplot(422);plot(sl);title('載波信號(hào)')；%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%調(diào)制e_2ask=st.*s1;subplot(423);plot(t,e_2ask);title('已調(diào)信號(hào)')；noise=rand(l,j);e_2ask=e_2ask+noise;%加入噪聲subplot(424);plot(t,e_2ask);title('加入噪聲的信號(hào)')；%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%相干解調(diào)at=e_2ask.*cos(2*pi*fc*t);at=at-mean(at);subplot(425);plot(t,at);title('相乘后信號(hào)')；[f,af]=T2F(t,at);%通過低通濾波器[t,at]=lpf(f,af,2*fm);subplot(426);plot(t,at);title('解調(diào)后波形')；%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%抽樣判決form=0:i-1;ifat(l,m*500+250)+0.5<0.5;forj=m*500+l: