L.I. Averina - Ph.D. (Phys.-Math.), Associate Professor, Department of Electronics, Voronezh State University. E-mail: averina@phys.vsu.ru
A.M. Bobreshov - Dr.Sc. (Phys.-Math.), Professor, Head of Electronics Department, Voronezh State University. E-mail: bobreshov@phys.vsu.ru
V.D. Shutov - undergraduate student, Department of Electronics, Voronezh State University. E-mail: vovchik888@gmail.com

In modern telecommunication systems, it is very important to achieve high data transfer rate. Difficult, complex methods of modulation of signal use to achievement of high speeds of transfer and simultaneously high spectral efficiency. These modulations have the big relation of the PAR that increases requirements to linearity of the power amplifier. High linearity is achieved by linearization schemes, a type choice active component and a bias point of an active component. Digital methods of a linearization intensively develop. For example, the linearization by predistortion in transmission signal considerably improves linearity at preservation of high efficiency of the amplifier. The method of digital predistortion has a number of advantages. First, in the microwave transmitters the power amplifier is very sensitive to structure changes. The method of predistortion doesn't assume change of parameters of the amplifier, and assumes inclusion on its input of the additional low-power device. Secondly, in the analog compensator, which principle of action is based on application of one or several nonlinear elements (usually diodes), it is almost impossible to operate device parameters purposefully. The digital compensator is free from this lack. In the end, application of digital methods of modulation and use of schemes of direct digital synthesis allow to create the digital compensator in the form of the hardware-software module which is a part of the modulator. Method of digital predistortion was stated. Possibility of an adaptive linearization of a transmitter was considered. Recommendations of for choice correcting function, an adaptation method, and also to the size and a way of filling of the correcting table are made. Both results of computer modeling, and experimentally received for the real device was presented. Results can be used further for design of the real transmitter to which high demands to linearity and electromagnetic compatibility is made.