Howtosignalprocessing
- How do you prevent aliasing in sampling?
- What are the examples of aliasing?
- How do you prevent aliasing while sampling a continuous time signal?
- What is Nfft in spectrogram?
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.
What are the examples of aliasing?
The "wagon wheel effect" is a familiar example of aliasing. In this optical illusion, spokes on a wheel appear to rotate at different rates or even backwards depending on the digital frame rate of the video.
How do you prevent aliasing while sampling a continuous time signal?
Aliasing is generally avoided by applying low-pass filters or anti-aliasing filters (AAF) to the input signal before sampling and when converting a signal from a higher to a lower sampling rate.
What is Nfft in spectrogram?
nfft tells you how many FFT points are desired to be computed per chunk. The default number of points is the largest of either 256, or floor(log2(N)) where N is the length of the signal. nfft also gives a measure of how fine-grained the frequency resolution will be.
