I’ve built a circuit with an analogue sensor (70 Hz bandwidth) connected to a 24 bit ADC, which is oversampling the signal at 10 kHz. Nyquist sampling theorem implies I should sample by at least 140 Hz to reconstruct the signal.
Currently (if I’ve understood oversampling correctly) I’m oversampling by a factor of $N = \frac{10000-140}{140} = 70$. As the minimum sampling frequency is the Nyquist rate, and oversampling is a factor $N$ times this minimum rate. My questions are:
- Does this oversampling only reduce the noise introduced from the output of the analogue sensor (given the low bandwidth of the sensor) to the end of the ADC process?
- How much can I reduce the oversampling (which introduces a processor overhead) by for a negligible increase in the amount of noise to the signal?
- Could I do anything else to reduce the amount of oversampling, e.g increase the ADC resolution?