Howtosignalprocessing
- How a band-limited signal can be sampled without aliasing?
- What causes aliasing?
- How do you prevent aliasing in sampling?
- Why is it necessary to limit the band of a signal?
How a band-limited signal can be sampled without aliasing?
Thus, band-limited signals can be sampled and fully recovered only when observing the Nyquist criterion. For bandpass signals the Nyquist criterion will ensure no aliasing only when the recovery of the signal is done with a bandpass filter; otherwise a higher sampling frequency will be required.
What causes aliasing?
Aliasing is the effect of new frequencies appearing in the sampled signal after reconstruction, that were not present in the original signal. It is caused by too low sample rate for sampling a particular signal or too high frequencies present in the signal for a particular sample rate.
How do you prevent aliasing in sampling?
The solution to prevent aliasing is to band limit the input signals—limiting all input signal components below one half of the analog to digital converter's (ADC's) sampling frequency. Band limiting is accomplished by using analog low-pass filters that are called anti-aliasing filters.
Why is it necessary to limit the band of a signal?
Band limiting ensures that the original input signal can be reconstructed exactly from the ADC's output samples when a sampling frequency ( Undesirable signals, above fs/2, of a sufficient level can create spectrum overlap and add distortion to the desired baseband signal.
