Instruments and Systems: Monitoring, Control, and Diagnostics Annotation << Back Research of interference of the modem of digital systems with amplitude manipulation when working in the channel with the gaussian noise YU.M. VESHKURTSEV The modem for digital systems of different purposes with amplitude manipulation is investigated in the new operating conditions. Important analytical dependences are obtained, by means of which its noise immunity at work in the channel with Gaussian noise is estimated. The basis of these dependences is the characteristic function of the signal with amplitude manipulation, which is used in the transmission of digital information. Due to the mathematical expectation of noise noise immunity modem decreased by 5 dB compared to its characteristics when working in the channel with "white" noise. Recommendations are given to eliminate the influence of numerical characteristics of Gaussian noise on the noise immunity of the modem. Keywords: amplitude manipulation, characteristic function, demodulator, modem, Gaussian noise, mathematical expectation, noise immunity, signal-to-noise ratio. DOI: 10.25791/pribor.09.2019.871 Contacts: - Pp. 21-26.