Comparison of Two Approaches to Modeling Additive White Gaussian Noise as It Acts on Arbitrary Signals

The purpose of this paper is to substantiate the correct method for modeling additive white Gaussian noise under conditions of using analog filtering when processing a signal-noise mixture. To achieve the result, two methods of noise modeling used in signal processing theory for Gaussian channels are considered: the first is a traditional simplified discrete method, and the second is a more complex, but functionally correct analog-discrete method. As a result of the comparison, the undeniable advantages of the analog-discrete method are proven. A conclusion was made about the preference of using the proposed new method, which ensures the complete adequacy of the noise model.