SSB(滤波法法)调制解调Matlab.m文件源码

set(gca,'XTick', [-10:10:10]);

set(gca,'XGrid','on');

%%

%-----------------经过低通滤波器

%画出理想低通滤波器

figure(5);

[LPF,f] = lp_f(length(der),Bw_eq,df1,fs,1); %求出低通滤波器

subplot(411);

plot(f,fftshift(abs(LPF))); %画出理想低通滤波器

xlabel('f');title('理想LPF');

axis([-f0-Bw_eq,f0+Bw_eq,-0.05,1.05]);

%%

%混频信号经过理想低通滤波器后的频谱及波形

DM = LPF.*derf; %理想低通滤波器输出的频谱

[dm] = F2T_new(DM,fs); %滤波器的输出波形

subplot(412);

plot(t,dm(1:Lt)); %画出经过低通滤波器后的解调波形 axis([0,t0,-max(dm)-0.2,max(dm)+0.2]);

xlabel('t');title('恢复信号');

set(gca,'YTick', [-1:0.5:1]);

set(gca,'YGrid','on');

subplot(413);

[dmf,dm,df1,f] = T2F_new(dm(1:Lt),dt,df,fs); %求LPF输出信号的频谱

plot(f,fftshift(abs(dmf))); %画出LPF输出信号的频谱 xlabel('f');title('恢复信号频谱');

axis([-fc,fc,0,max(abs(dmf))+0.1]);

set(gca,'XTick', [-10:10:10]);

set(gca,'XGrid','on');

%%

subplot(414);

plot(t,m(1:Lt)); %画出调制信号波形

xlabel('t');title('调制信号');

set(gca,'YTick', [-R:1:R]);

axis([0,t0,-R-0.3,R+0.3])

xlabel('t');title('调制信号');