Help decoding 12KHZ tone?

[bobcat1]

Hi All

I need to decode a 12KHz tone using Grotzel (DFT) algorithm

Can you please show me how to calculate the ADC sample rate needed to decode this tone ,and minimum number of samples needed?

Thanks

Bobi

 

[FvM]

In the general case (I guess, you already know) the Nyquist criterion must be kept, also an anti-aliasing filter is necessary to avoid downmixing of above fs/2 input signal components.

The required sample length depends on the intended bandwidth. As with any FFT, windowing of the sequence is required to get a smooth filter shape. Simply, the window FFT is the filter transmission function, e.g. rectangular window (= no window function applied) has an unpleasant sin(x)/x shape.