More about Sampling

Aliasing

Aliasing is when different continuous signals become indistinguishable when sampled, this might happen when sampling too slow. It can also refer to the distortion that occurs when a signals are sampled and reconstructed as aliases of the original signals.

Here is an example of aliasing:

Like we can see in this images, the samples that we are getting out of the yellow wave, can be also samples in the blue one.

Script for Matlab: clear all;

t=0:.01:1;

T=0.20;

ts=0:T:1;

f1=2;

f2=1/0.125;

plot(t,cos(2*pi*f2*t),'b-',ts,cos(2*pi*f1*ts),'r*',t,cos(2*pi*f1*t),'y-');

plot(ts,cos(2*pi*f1*ts),'r*',t,cos(2*pi*f1*t),'y-');