(圓滿word版)2ASK、2FSK、2PSK數字調制系統Matlab實現及性能分析(圓滿word版)2ASK、2FSK、2PSK數字調制系統Matlab實現及性能分析(圓滿word版)2ASK、2FSK、2PSK數字調制系統Matlab實現及性能分析2ASK、2FSK、2PSK數字調制系統的Matlab實現及性能分析比較前言：數字信號有兩種傳輸方式，分別是基帶傳輸方式和調制傳輸方式，即帶通，在實質應用中，因基帶信號含有大批低頻重量不利于傳達，因此必然經過載波和調制形成帶通訊號，經過數字基帶信號對載波某些參量進行控制，使之隨機帶信號的變化而變化，這這一過程即為數字調制。數字調制為信號長距離高效傳輸供給保障，現已寬泛應用于生活和生產中。其他依據控制載波參量方式的不一樣樣，數字調制主要有調幅〔ASK〕，調頻(FSK)，調相(PSK)三種根本形式。本次課題針關于二進制的2ASK、2FSK、2PSK進行討論，應用Matlab矩陣實驗室進行仿真，分析和改正，經過仿真系統生成一個人機交互界面，以利于仿真系統的操作。經過對系統的仿真，更為直觀的認識數字調制系統的性能及影響其性能的各樣要素，以便于比較，討論和改進。重點詞：數字，載波，調制，2ASK，2FSK，2PSK，Matlab，仿真，性能，比較，分析正文：一.數字調制與解調原理1.12ASK1〕2ASK2ASK就是把頻次、相位作為常量，而把振幅作為變量，信息比特是經過載波的幅度來傳達的。因為調制信號只有0或1兩個電平，相乘的結果相當于將載頻或許關斷，或許接通，它的實質意義是當調制的數字信號"1時，傳輸載波；當調制的數字信號為"0"時，不傳輸載波。表達式為：Acosct,當ak1s2ASK(t)0，當ak01.22FSK2FSK能夠看做是2個不一樣樣頻次的2ASK的疊加，其調制與解調方法與2ASK差不多，主要頻次F1和F2，不一樣樣的組合產生所要求的2FSK調制信號。公式以下：Acos1t,當a1s2FSK(t)k2t，當ak0Acos1.32PSK2PSK以載波的相位變化為基準，載波的相位隨數字基帶序列信號的1或許0而改變，平常用已經調制完的載波的0或許π表示數據1或許0，每種相位與之一一對應。二．數字調制技術的仿真切現本課程設計需要借助MATLAB的M文件編程功能，對進行調制與解調的設計，并繪制出調制與解調后的波形，誤碼率的狀況分析，軟件仿真可在已有平臺上實現。1.2ASK代碼主函數closeallclearalln=16;fc=1000000;bitRate=1000000;N=50;%noise=ti;noise=10;signal=source(n,N);%生成二進制代碼transmittedSignal=askModu(signal,bitRate,fc,N);%調制后信號signal1=gussian(transmittedSignal,noise);%加噪聲configueSignal=demoASK(signal1,bitRate,fc,n,N);source代碼functionsendSignal=source(n,N)sendSignal=randint(1,n)bit=[];fori=1:length(sendSignal)ifsendSignal(i)==0bit1=zeros(1,N);elsebit1=ones(1,N);endbit=[bit,bit1];endfigure(1)plot(1:length(bit),bit),title('transmittingofbinary'),gridon;axis([0,N*length(sendSignal),-2,2]);endaskModu代碼functiontransmittedSignal=askModu(signal,bitRate,fc,N)%signal為輸入信號，bitrate為bit速率，fc調制信號頻次，N%signal=[00101101];bitRate=1000000;fc=1000000;N=32;t=linspace(0,1/bitRate,N);c=sin(2*pi*t*fc);transmittedSignal=[];fori=1:length(signal)transmittedSignal=[transmittedSignal,signal(i)*c];endfigure(2)%畫調制圖plot(1:length(transmittedSignal),transmittedSignal);title('ModulationofASK');gridon;figure(3)%畫頻譜實部m=0:length(transmittedSignal)-1;F=fft(transmittedSignal);plot(m,abs(real(F))),title('ASK_frequency-domainanalysisreal');gridon;%figure(4)畫頻譜虛部%plot(m,imag(F));title('ASK_frequency-domainanalysisimag');%gridon;endCheckRatePe代碼functionPeWrong=CheckRatePe(signal1,signal2,s)rights=0;wrongs=0;forki=1:s-2if(signal1(ki)==signal2(ki))rights=rights+1;elsewrongs=wrongs+1;endendPeWrong=wrongs/(wrongs+rights);enddemoASK代碼functionbitstream=demoASK(receivedSignal,bitRate,fc,n,N)loadnumsignal1=receivedSignal;signal2=abs(signal1);%??á÷signal3=filter(num1,1,signal2);%LPF,°ü???ì2¨IN=fix(length(num1)/2);%?ó3ùê±??bitstream=[];LL=fc/bitRate*N;i=IN+LL/2;while(i<=length(signal3))%?D??bitstream=[bitstream,signal3(i)>=0.5];i=i+LL;endfigure(6)subplot(3,1,1);%接收波形plot(1:length(signal1),signal1);title(terminal(includingnoise)');gridsubplot(3,1,2);%接收整流后波形plot(1:length(signal2),signal2);title(

on;

'Waveofreceiving'Waveofcommutate'

);grid

on;subplot(3,1,3);%包絡檢波波形plot(1:length(signal3),signal3);title(

'WaveofLPF'

);grid

on;bit=[];for

i=1:length(bitstream)if

bitstream(i)==0bit1=zeros(1,N);elsebit1=ones(1,N);endbit=[bit,bit1];endfigure(7)%解調后的二進制波形plot(bit),title('binaryofreceivingterminal'),gridon;axis([0,N*length(bitstream),-2.5,2.5]);endgussian代碼%加高斯白噪聲functionsignal=gussian(transmittedSignal,noise)signal=sqrt(2)*transmittedSignal;signal=awgn(signal,noise);figure(5)plot(1:length(signal),signal);title('Waveincludingnoise'),gridon;endfsk主函數代碼closeallclearalln=16;%二進制代碼長度f1=18000000;%

頻次1f2=6000000;%

頻次2bitRate=1000000;%bit速率N=50;%碼元寬度%noise=ti;noise=10;%家性噪聲大小signal=source(n,N);%產生二進制代碼transmittedSignal=fskModu(signal,bitRate,f1,f2,N);%調制signal1=gussian(transmittedSignal,noise);%加噪聲configueSignal=demoFSK(signal1,bitRate,f1,f2,N);%解調source代碼%二進制信號產生函數functionsendSignal=source(n,N)sendSignal=randint(1,n)bit=[];fori=1:length(sendSignal)ifsendSignal(i)==0bit1=zeros(1,N);elsebit1=ones(1,N);endbit=[bit,bit1];endfigure(1)plot(bit),title('transmittingofbinary'),gridon;axis([0,N*length(sendSignal),-2.5,2.5]);endfskModu代碼%頻次調制函數functiontransmittedSignal=fskModu(signal,bitRate,f1,f2,N)t=linspace(0,1/bitRate,N);c1=sin(2*pi*t*f1);%c2=sin(2*pi*t*f2);%

調制信號調制信號

12transmittedSignal=[];for

i=1:length(signal)%

調制ifsignal(i)==1transmittedSignal=[transmittedSignal,c1];elsetransmittedSignal=[transmittedSignal,c2];endendfigure(2)%

畫調制后波形圖plot(1:length(transmittedSignal),transmittedSignal);title(ofFSK');gridon;figure(3)%畫調制后頻譜圖m=0:length(transmittedSignal)-1;F=fft(transmittedSignal);plot(m,abs(real(F))),title('ASK_frequency-domainanalysisreal'gridon;end

'Modulation);demoFSK代碼functionbitstream=demoFSK(receivedSignal,bitRate,f1,f2,N)load

numsignal1=receivedSignal;signal2=filter(gaotong,1,signal1);

%經過HPF，獲得高通重量signal3=abs(signal2);

%整流signal3=filter(lowpass,1,signal3);

%經過低通，形成包絡bitstream=[];IN1=fix(length(lowpass)/2)+fix(length(gaotong)/2);%延緩時間bitstream1=[];LL=N;i=IN1+LL/2;while(i<=length(signal3))bitstream1=[bitstream1,signal3(i)>=0.5];i=i+LL;endbitstream1figure(5)subplot(3,1,1);plot(1:length(signal1),signal1);title(terminal(includingnoise)');gridsubplot(3,1,2);plot(1:length(signal2),signal2);title(subplot(3,1,3);plot(1:length(signal3),signal3);title(

%每個bit%裁決on;

的抽樣點數'Waveofreceiving'AfterPassing'AfterPassing

HPF');gridLPF');grid

on;on;signal4=filter(daitong,1,signal1);signal5=abs(signal4);%整流signal5=filter(lowpass,1,signal5);IN2=fix(length(lowpass)/2)+fix(length(daitong)/2);bitstream2=[];LL=N;%每個biti=IN2+LL/2;while(i<=length(signal5))%裁決bitstream2=[bitstream2,signal5(i)>=0.5];i=i+LL;endbitstream2figure(6)subplot(3,1,1);plot(1:length(signal1),signal1);title(terminal(includingnoise)');gridon;subplot(3,1,2);plot(1:length(signal4),signal4);title(subplot(3,1,3);plot(1:length(signal5),signal5);title(

%經過BPF獲得低頻重量%經過LPF，形成包絡的的抽樣點數'Waveofreceiving'AfterPassing'AfterPassing

%延緩時間BPF');gridon;LPF');gridon;fori=1:min(length(bitstream1),length(bitstream2))%裁決if(bitstream1(i)>bitstream2(i))bitstream(i)=1;elsebitstream(i)=0;endendbitstreambit=[];

%接收端波形for

i=1:length(bitstream)if

bitstream(i)==0bit1=zeros(1,N);elsebit1=ones(1,N);endbit=[bit,bit1];endfigure(7)plot(bit),title(

'binaryofreceivingterminal'

),grid

on;axis([0,N*length(bitstream),-2.5,2.5]);endCheckRatePe代碼functionPeWrong=CheckRatePe(signal1,signal2,s)rights=0;wrongs=0;forki=1:s-2if(signal1(ki)==signal2(ki))rights=rights+1;elsewrongs=wrongs+1;endendPeWrong=wrongs/(wrongs+rights);endgussian代碼functionsignal=gussian(transmittedSignal,noise)signal=sqrt(2)*transmittedSignal;signal=awgn(signal,noise);figure(4)plot(1:length(signal),signal),title('AddingNoise');gridon;end2psk主函數代碼closeallclearalln=16;%二進制碼長fc=1000000;%載波頻次bitRate=1000000;信息頻次N=50;%碼寬noise=10;%信道加性噪聲大小signal=source(n,N);生成二進制代碼transmittedSignal=bpskModu(signal,bitRate,fc,N);對信號進行調制并進行頻譜分析signal1=gussian(transmittedSignal,noise)%加信道噪聲configueSignal=demoBPSK(signal1,bitRate,fc,n,N);%信號解調source代碼functionsendSignal=source(n,N)sendSignal=randint(1,n)bit=[];fori=1:length(sendSignal)ifsendSignal(i)==0bit1=zeros(1,N);elsebit1=ones(1,N);endbit=[bit,bit1];endfigure(1)plot(bit),title('transmittingofbinary'),gridon;axis([0,N*length(sendSignal),-2.5,2.5]);endbpskModu代碼functiontransmittedSignal=bpskModu(signal,bitRate,fc,N)t=linspace(0,1/bitRate,N);c1=sin(2*pi*t*fc);c2=sin(2*pi*t*fc+pi);transmittedSignal=[];fori=1:length(signal)ifsignal(i)==1transmittedSignal=[transmittedSignal,c1];elsetransmittedSignal=[transmittedSignal,c2];endendfigure(2)%畫調制圖plot(1:length(transmittedSignal),transmittedSignal);title(ofBPSK');gridon;figure(3)%畫頻譜圖m=0:length(transmittedSignal)-1;F=fft(transmittedSignal);plot(m,abs(real(F))),title('BPSK_frequency-domainanalysisreal'gridon;end

'Modulation);CheckRatePe代碼functionPeWrong=CheckRatePe(signal1,signal2,s)rights=0;wrongs=0;forki=1:s-2if(signal1(ki)==signal2(ki))rights=rights+1;elsewrongs=wrongs+1;endendPeWrong=wrongs/(wrongs+rights);enddemoBPSK代碼functionbitstream=demoBPSK(receivedSignal,bitRate,fc,n,N)loadnum%讀取num儲蓄的低通濾波用的數據signal1=receivedSignal;t=linspace(0,1/bitRate,N);c=sin(2*pi*t*fc);signal=[];fori=1:nsignal=[signal,c];endsignal2=signal1.*signal;%乘同頻同相sinsignal3=filter(num1,1,signal2);

%LPF,

包絡檢波

3IN=fix(length(num1)/2);

%?延緩時間bitstream=[];LL=fc/bitRate*N;i=IN+LL/2;while(i<=length(signal3))

%裁決bitstream=[bitstream,signal3(i)>=0];i=i+LL;endfigure(5)subplot(3,1,1);%畫接收的包括噪聲的波形plot(1:length(signal1),signal1);title(terminal(includingnoise)');gridon;subplot(3,1,2);%相關解調波形plot(1:length(signal2),signal2);title(Fuction');gridon;subplot(3,1,3);%包絡檢波波形plot(1:length(signal3),signal3);title(

'Waveofreceiving'AfterMultiplingsin'WaveofLPF'

);grid

on;bit=[];fori=1:length(bitstream)ifbitstream(i)==0bit1=zeros(1,N);elsebit1=ones(1,N);endbit=[bit,bit1];endfigure(6)

二進制接收信號波形plot(bit);title(

'binaryofreceivingterminal'

);grid

on;axis([0,N*length(bitstream),-2.5,2.5]);endgussian代碼functionsignal=gussian(transmittedSignal,noise)signal=sqrt(2)*transmittedSignal;signal=awgn(signal,noise);figure(4)plot(1:length(signal),signal),gridon;title('Addingnoise')end三種調制方式的性能比較:loadPeRate;loadPeRatep;%賠償偏差fpeask(15)=1e-3;fpe