Calcolatore Rapporto Segnale-Rumore (SNR) — Formula
## How Aliasing Works
When a signal exceeds the Nyquist frequency (half the sampling rate), it "folds" back into the representable range, appearing as a lower frequency.
### Formula
The aliased frequency is found by folding the signal into the first Nyquist zone:
**f_alias = |f_signal - round(f_signal / f_sample) x f_sample|**
If this result is above Nyquist, subtract from the sampling rate.
### Example
A 30 kHz tone sampled at 44.1 kHz aliases to 14.1 kHz (44.1 - 30 = 14.1 kHz).
When a signal exceeds the Nyquist frequency (half the sampling rate), it "folds" back into the representable range, appearing as a lower frequency.
### Formula
The aliased frequency is found by folding the signal into the first Nyquist zone:
**f_alias = |f_signal - round(f_signal / f_sample) x f_sample|**
If this result is above Nyquist, subtract from the sampling rate.
### Example
A 30 kHz tone sampled at 44.1 kHz aliases to 14.1 kHz (44.1 - 30 = 14.1 kHz).
Esempio Risolto
A 30 kHz signal sampled at 44.1 kHz.
- Nyquist: 44,100 / 2 = 22,050 Hz
- 30,000 > 22,050, so aliasing occurs
- Alias: |30,000 - 1 x 44,100| = 14,100 Hz
- The 30 kHz signal appears as 14,100 Hz