V.E. Dementiev - Ph. D. (Eng.), Associate Professor, Department «Telecommunications», Ulyanovsk State Technical University. E-mail: vitawed@mail.ru S.V. Voronov - Ph. D. (Eng.), Junior Research Scientist, Department «Radio Engineering», Ulyanovsk State Technical University. E-mail: s.voronov@ulstu.ru A.G. Frenkel - Post-graduate Student, Department «Telecommunications», Ulyanovsk State Technical University. E-mail: j.skvoll@gmail.com