DSP Basics – Aliasing

• Sample at 40 kHz. Nyquist freq is 20kHz.

• 19 kHz signal appears at 19 kHz

• 20 kHz signal appears at 20 kHz

• 21 kHz signal appears at 19 kHz

• 39 kHz signal appears at 1 kHz

• 40 kHz signal appears at 0 kHz

• 41 kHz signal appears at 1 kHz

• 59 kHz signal appears at 19 kHz