The solution is suggested for the problem of detecting a discrete information signal. It is based on estimating the dispersion of the logarithm of the ratio of the amplitudes of the neighboring information symbols. And it makes it possible to provide a specified false alarm probability in a channel with an unknown level of Gaussian noise. In this case, the missing probability is determined only by the signal-to-noise ratio. Thus, one can measure the quality of the operating communication channel without interfering with the transmitted signals. The probabilistic properties of the dispersion are considered, the calculated relationships for detection characteristics are obtained, and a statistical simulation of the synthesized algorithm is carried out for detecting a phase-shift keyed signal. The high efficiency of the proposed detector is established and confirmed over a wide signal-to-noise ratio range. The introduced algorithm can be used while monitoring the state of communication channels in order to control them in a multi-channel information transmission system. #CSOC1120.