Петров П.Т.

There is a definition of the basic parameters of the real signals and evaluation of the simplest and widely used mathematical models to represent them. The disaccord between the engineering world with the real signals and the world of mathematicians with the mathematical models for these signals is obvious especially in the following theoretical points: the classical sampling theorem, Fourier series, Dirichlet conditions, Gibbs phenomenon, Dirac function (delta function), Dirac comb, sin(x)/x function, unit step function, staircase functions (based on rectangles) and theirs derivatives. These models are declared misrepresentatives and attempts to reject, modify and replace them were made. Postulates about real signals are formulated. Examples with dual tone and multi tone multi frequency signals are given. Theorems about sampling the simplest band-limited signals in order to calculate theirs parameters are shown.