Application of Incoherent Multi-Frequency Signals for Information Transmission in a Nonstationary Hydroacoustic Environment

—A class of digital incoherent methods of information transmission based on multi-frequency signals for mobile underwater complexes is presented, which does not require regular and accurate estimation of channel parameters and is a priori resistant to various types of interference in nonstationary hydroacoustic communication channels, and is oriented to solving communication and navigation problems for underwater robotic complexes. The limitation of spectral efficiency of such multi-frequency systems of information transmission by the value of 0.5 bits/s/Hz in various frequency ranges, nonstationary hydrological conditions, with achievement of the maximum range at acceptable levels of error probability during information decoding is shown. The operability of the proposed class of multi-frequency multiplexing methods was confirmed by numerical and in situ sea experiments on the shelf at distances from 2.5 to 7 km with the mutual drifting of ships and with sea waves of up to 3 points.