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Aliasing

Basics

What is Aliasing
  • Aliasing is an effect of our Discrete-Time definition that causes different signals to become indistinguishable (aliases of one another, when sampled)
  • In the example below, these two different waveforms appear identical when sampled
    • Pasted image 20221230134039.png
  • In other words, there's multiple solutions which satisfies the \(x[n]\) for any given problem.
When does Aliasing Occur + The Nyquist Frequency
  • Aliasing occurs when \(\(\large F_{signal} \ge \frac{F_{s}}{2}\)\)
  • The Nyquist Frequency \(\large F_\text{Nyquist}=2|F_\text{signal}|<F_s\) defines the minimum which the sampling frequency must exceed to avoid aliasing, aka the maximum input frequency at a given sampling frequency to avoid aliasing.

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