資源描述：
《基于matlab的 am,fm調(diào)制與解調(diào)報告》由會員上傳分享，免費在線閱讀，更多相關(guān)內(nèi)容在教育資源-天天文庫。
1、AM調(diào)制與解調(diào)100%%AMμ÷??figure('Name','D?o?μ÷??1y3ì?D2¨D??°???μ?×','NumberTitle','off')a0=1;f0=2000;fc=20000;fs=1000000;t=[1:0.000001:4];am1=0*cos(2*pi*f0*t);%μ÷??D?o?am=a0+am1;t1=cos(2*pi*fc*t);%??2¨s_am=am.*t1;AM1=fft(am1);T1=fft(t1);S_AM=fft(s_am);f=(0:3000000)*fs/3000001-fs/2;subplot(3,2,1);plot(t(1
2、:1000),am1(1:1000));title('D??￠D?o?2¨D?');subplot(3,2,2);plot(f,fftshift(abs(AM1)));title('D??￠D?o??μ?×');subplot(3,2,3);plot(t(1:1000),t1(1:1000));title('??2¨D?o?');subplot(3,2,4);plot(f,fftshift(abs(T1)));title('??2¨D?o??μ?×');subplot(3,2,5);plot(t(1:1000),s_am(1:1000));title('ò?μ÷D?o?');subplot
3、(3,2,6);plot(f,fftshift(abs(S_AM)));title('ò?μ÷D?o??μ?×');%2úéú??éùfigure('Name','ìí?ó??éù?°′?í¨??2¨1y3ì2¨D??°???μ?×','NumberTitle','off');snr=5;y=awgn(s_am,snr);fcuts=[16000175002250024000];mags=[010];devs=[0.050.010.05];[n,Wn,beta,ftype]=kaiserord(fcuts,mags,devs,fs);hh=fir1(n,Wn,ftype,kaiser(n+
4、1,beta),'noscale');[H,f]=freqz(hh,1,1024,fs);st_p=fftfilt(hh,y);Q=fft(st_p);Y=fft(y);f=(0:3000000)*fs/3000001-fs/2;subplot(2,2,1);plot(t(1500001:1501000),y(1500001:1501000));title('ìí?ó??éùoóD?o?2¨D?');subplot(2,2,2);plot(f,fftshift(abs(Y)));title('ìí?ó??éùoóD?o??μ?×');subplot(2,2,3);plot(t(150000
5、1:1501000),st_p(1500001:1501000));title('′?í¨??2¨oóD?o?2¨D?');subplot(2,2,4);plot(f,fftshift(abs(Q)));title('′?í¨??2¨oóD?o??μ?×');%?aμ÷figure('Name','?à?é?aμ÷?ùμ?2¨D??°???μ?×','NumberTitle','off');ss_am=st_p.*t1;SS_AM=fft(ss_am)f=(0:3000000)*fs/3000001-fs/2;subplot(2,1,1);plot(t(1500001:1503000),s
6、s_am(1500001:1503000));title('?à3?D?o?');subplot(2,1,2);plot(f,fftshift(abs(SS_AM)));title('?à3?D?o??μ?×');fcuts1=[2500,30000];mags1=[10];devs1=[0.010.05];[n,Wn,beta,ftype]=kaiserord(fcuts1,mags1,devs1,fs);hh1=fir1(n,Wn,ftype,kaiser(n+1,beta),'noscale');[H,f]=freqz(hh1,1,1024,fs);m0=fftfilt(hh1,ss
7、_am);M0=fft(m0);f=(0:3000000)*fs/3000001-fs/2;figuresubplot(2,1,1);plot(t(1500001:1501000),m0(1500001:1501000));title('?aμ÷D?o?');subplot(2,1,2);plot(f,fftshift(abs(M0)));title('?aμ÷D?o??μ?×');50%%AMμ÷??figure('N
