Howtosignalprocessing
- What is difference between sampling and aliasing?
- Does digital filter solve the problem of aliasing?
- How is sampling rate and aliasing related?
- What is aliasing and antialiasing filter?
What is difference between sampling and aliasing?
Aliasing is when a continuous-time sinusoid appears as a discrete-time sinusoid with multiple frequencies. The sampling theorem establishes conditions that prevent aliasing so that a continuous-time signal can be uniquely reconstructed from its samples. The sampling theorem is very important in signal processing.
Does digital filter solve the problem of aliasing?
With oversampling, a higher intermediate digital sample rate is used, so that a nearly ideal digital filter can sharply cut off aliasing near the original low Nyquist frequency and give better phase response, while a much simpler analog filter can stop frequencies above the new higher Nyquist frequency.
How is sampling rate and aliasing related?
When the sampling rate is not large enough (not larger than 2B Hz), then interference among adjacent bands will occur, and this results in the phenomenon of aliasing. In this case, the original signal cannot be recovered from the sampled signal.
What is aliasing and antialiasing filter?
An anti-aliasing filter is just a low pass filter with the cutoff frequency (i.e., the -3 dB frequency) set to the Nyquist frequency. This filter cuts out any higher order frequency content in the input signal as any frequencies higher than the Nyquist frequency would be aliased.
