Question about SNR in continuous and discrete domain How to make sure the discrete domain's SNR equals to the corresponding SNR of continuous domain?


  If the definition of SNR in continuous domain is:
  
  $$SNR=\frac{\int_T|s(t)|^2dt}{noiseVariance} $$
  
  if we sampled $s(t)$ ($T_s$ is the sample period) then what is the
  corresponding SNR of the discrete domain? Is
  
  $$SNR=\frac{\sum_{n=1}^{N}|s(nT_s)|^2dt}{noiseVariance} $$ 
  
  ?
In your $snr$ expression, if you put a $1/N$ ratio in front of the numerator summation you'll have the standard expression for SNR with regard to sampled data (digital data).