Tytarchuk O. Upgrading of quality characteristics of multifrequency narrow-band transmission paths

The object for research is narrow-band multifrequency fiber-optical and radio relay paths of transmission systems. The subject for research is nonlinear distortions in multifrequency paths of transmission systems. The aim if this work is to upgrade quality characteristics of transmission systems with multifrequency division multiplexing by means of estimation of nonlinear distortions and setting out of requirements and restrictions for transmission path components. The technique for estimation of power of combinational products of nonlinearity in narrow-band paths of multifrequency transmission systems, in particular in fiber-optical systems with wavelength division multiplexing is developed. Exact analytical calculation ratios of products of nonlinearity of the third order of the first class of type 2fi - fj and fi + fj - fk are derived, namely: gross products in operating frequency band and the amount of combinations product in the most poor channel depending on the number of component signals. The calculation procedure of nonlinear distortions and signal immunity in narrow-band paths of multifrequency transmission systems is proposed which obtained the further development. The area of application is telecommunication systems.