modulation.m

对数字信号进行分析

function [modu1]=modulation(frames1,frames2,tb,fs1,fs2)
runum1=length(frames1);
runum2=length(frames2);
t1=tb:tb:tb*runum1;
% t2=1:1:1*runum1;
cos1=cos(2*pi*fs2*t1);
frames1=frames1.*cos1;
sin1=sin(2*pi*fs2*t1);
frames2=frames2.*sin1;
modu1=frames1+frames2;
figure
plot(t1,modu1)
% figure
% plot(t1,cos1)
f1=1:fs1/runum2:fs1;
X=abs(fft(modu1));
X=10*log10(X);
figure
plot(f1,X)
title('未随机化频谱图')
xlabel('频率Hz')
ylabel('幅度(dB)')