Limit Energy-Spectral Efficient Transmission of Signals and Short Codes Using Adaptive Analog Modulators

The paper discusses new class of narrowband adaptive feedback communication systems (AFCS) transmitting signals and short codes without coding. The research shows that optimal adjusted over feedback channel analog modulator efficiently realizes the functions of ideal coder, and power-spectral efficiency of AFCS attains the limits established by the information theory. The latter one permits to simplify the construction of the forward transmitter (FT), as well to reduce its energy consumption, cost and sizes. It is shown that both analog and short codes can be transmitted by AFCS with the limit spectral and energy efficiency, as well with given reliability and accuracy. The basic problems of AFCS implementation are discussed also.