- The phenomenon of a high frequency spectrum of original signal x(t) taking on identity of lower frequency spectrum of sampled signal is called aliasing or fold over.
Effects of aliasing
Loss of some of information in original signal x(t).
Preventive measures:
- Use of antialising filter or pre-filter
- Using Nyquist criteria for sampling signal x(t),
f>2W , where W is maximum sampling frequency spectrum of original signal x (t).