close all;
clear all;

fsig=100;
fvz=1000;
N=64;
A=1;

Tvz=1/fvz;
t=0:Tvz:Tvz*(N-1);
sigbase=A*sin(2*pi*fsig*t);
plot(t,sigbase,'k-');
hold on;
plot(t-(N-1)*Tvz,sigbase,'k-');
plot(t+(N-1)*Tvz,sigbase,'k-');
axis([-N*Tvz N*Tvz -1 1]);
grid on;
zoom on;
shg;