# Sampling Rate and SNR

Assume I have a signal that oscillates between 10KHz and 9Khz every 500msec (Change happens linearly, so at t=0, it is 10KHz and it goes to 9.5Kz at t=250msec and 9KHz at t=500msec and frequency start to increase and goes back to 10KHz at 1 sec and this goes on)

Assume I sample this signal at 50Khz and I do fft to find out what's the frequency. But due to sampling rate, I have to accumulate some samples where the interest frequency is slowly shifting.

If I were to sample at 500KHz or even 5MHz, can I get a better SNR? (The assumption here is that I can sample for a shorter duration -still several cycles of the target frequency in time domain- and this will provide a less spread signal in a given time and better fft snr. )

My gut tells me, this won't help but I like to ask the crowd.

• You are just looking in the sample rate for SNR. i think that the bith dept of your AD-converter is more important. With a very high sample rate you just measuring just the same value... Apr 14, 2016 at 10:31
• I realize this is an old question, but I think both the answers and comments omit an important point. If your signal has a single frequency, sampling more densely will improve the SNR of your amplitude estimate, but if it reduces your sampling duration (e.g., your number of samples is constant), that amplitude SNR comes at the expense of frequency resolution (and frequency SNR). The same tradeoff applies when you estimate instantaneous frequency of a variable frequency (e.g., chirped) signal. May 17, 2022 at 4:37