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Could you elaborate on why oversampling is important? With Nyquist I was generally of the impression that 2 x bandwidth should be just fine, but in practice osc
by revelation 11y ago
Could you elaborate on why oversampling is important? With Nyquist I was generally of the impression that 2 x bandwidth should be just fine, but in practice oscilloscopes (just one example) seem to have five times or more sampling rate than bandwidth.
- lpmay 11y agoThe Nyquist rate is the theoretical minimum that allows you to distinguish one frequency from another. Sampling a higher frequency will cause an alias component to appear. This means that in practice, there must be analog band-limiting before the signal is sampled to reject any out of band signals before they are aliased to an in-band frequency and cannot be removed. The closer the band limiting cutoff comes to the nyquist frequency the more extreme the roll-off requirements for this band-limiting. Oversampling relaxes the band-limiting requirements, and can also increase the bit depth at lower sample rates. See PDM microphones for an example where this is taken to the extreme.