R. N. Mukha - Head of Projects for Tropospheric Communication Systems, JSC «MNIRTI». E-mail: r.muha@mnirti.ru A. V. Shevyrev - Dr.Sc. (Eng.), Deputy General Director, JSC «MNIRTI». E-mail: A.Shevurev@mnirti.ru T. G. Tarakanova - Engineer, JSC «MNIRTI». E-mail: t.tarakanova @ mnirti.ru O. A. Chinenova - Engineer, JSC «MNIRTI». E-mail: astra@mnirti.ru

Compact noise-protected tropospheric station «Ladya» represents transported digital over-the-horizon communications station with small energy consumption, which functioning uses, a principle of package reception - transfers with a choice of optimum frequency which is patented by MNIRTI. The principle of work of station «Ladya» and the basic technical decisions realised in the station are considered. Comparative characteristics of small-sized stations of foreign and a domestic production are resulted. Application possibility in stationary communication lines is estimated and tendencies of development of tropospheric terminals are considered. Comparative calculation of a noise stability of communication systems from the multifrequency signals and optimal frequency, working in the tropospheric channel is resulted. The used method of a choice of optimum frequency allows us to reduce power of the transmitter of station by 2-3 times, lower essentially energy consumption of the station, its cost, weight and overall dimensions.