A. V. Gerasimov, B. S. Lobanov, N. V. Milovanova, N. S. Makeenkova, V. I. Nefedov, S. V. Esin

Mobile communication systems operate on the principle a lot of the station access, which refers to the possibility of handling multiple mobile stations to one base station or satellite repeater when subscribers can simultaneously transmit and receive information through them. In the transmission paths used by multi-frequency (group) signals with complex modulation types, and therefore their working band is always great. One of the frequently used and promising methods for complex modulation is the modulation multi-carrier (MMN), due to resistance of this type of modulation to multipath propagation and the efficiency of software - hardware implementation. MMN - signals are significantly changing the amplitude envelope of the group that due to the nonlinearity of two-way transmission path leads to a number of parasitic effects which degrade the efficiency and bandwidth of communication systems. Treatment group MMN - signals used in transmission paths of mobile communications systems, requires a highly linear multi-input transistor amplifiers, microwave power range, related to nonlinear dynamic systems. Considered harmonic analysis of output spectrum of the transistor amplifier with the simultaneous use of several frequencies by the quadrature components. Advantages and limitations of the method compared with others. The method is applicable to the analysis of output power amplifiers of mobile communication systems, digital television.