close all;
clear all;

fsig=15.625;
fvz=2000;
N=128;
A=1;

Tvz=1/fvz;
t=0:Tvz:Tvz*(N-1);
t2=0:1:127;
sig(1:65)=1;
sig(66:128)=-1;
plot(t2,sig,'k-');
hold on;
plot(t2,1.275*sin(2*pi*fsig*t),'k--');
plot(t2,0.4305*sin(3*2*pi*fsig*t),'k--');
plot(t2,1.275*sin(2*pi*fsig*t)+0.4305*sin(3*2*pi*fsig*t),'k-');

axis([0 128 -1.4 1.4]);

grid on;
zoom on;
shg;