  The paper presents original approach to concurrent optimization of the
transmitting and receiving parts of adaptive communication systems (CS) with
feedback channels. The results of research show a possibility and the way of
designing the systems transmitting the signals with a bit rate equal to the
capacity of the forward channel under given bit-error rate (BER). The results
of work can be used for design of different classes of high-efficient low
energy/size/cost CS, as well as allow further development and extension.
