A paper I am reading (Linear and Nonlinear Encoding Properties of an Identified Mechanoreceptor on the Fly Wing Measured with Mechanical Noise Stimuli) defines power level for a white-noise signal as the area under the autocorrelation function of the signal.
What exactly is power level? I couldn't find a proper definition for it. Is it average or RMS power?
Should I take the autocorrelation in frequency domain or time domain?
autocorrStim = conv(stim,-stim); powerLevel = sum(autocorrStim);
stim is the white-noise signal. Is this implementation correct?