I have a bandlimited analog signal for which I want to find the peak value in real time. The signal is sampled and processed digitally at just enough sampling rate. Since the peak of the analog signal may not be sampled exactly, taking the maximum of the digital samples would give a lower than actual value. So how do I find the peak?
Theoretically, the only way I can think of, is to upsample the signal using an ideal sinc interpolation filter to very high sampling rate, so that we obtain a sample close to the actual peak of the analog signal. Then we can just take the maximum of the digital samples. But this seems roundabout and computationally expensive. Is there is a simpler method to do this?