Instruments and Systems: Monitoring, Control, and Diagnostics Annotation << Back Modem with integrated virtual filter YU.M. VESHKURTSEV New knowledge of the characteristic function of random processes makes it possible to improve the characteristics of different devices in instrument making. The work deals with modem and filter. On the example of noise immunity, the possible increase by several orders of magnitude of this characteristic in modems of the new generation, the description and structure of which have been published in modern literature over the last year, is theoretically justified. The following results of theoretical studies in the direction of dynamic chaos according to arcsine law concern a structure from a modem and a filter operating in probability space. Such a structure theoretically allows the operation of digital communication systems with amplitude manipulation at signals 22 dB less noise. At the same time noise immunity of digital systems is maintained high, and probability of errors has value and less. A virtual filter modem is being developed for digital systems needed in the future to implement digital technologies. Keywords: modem, filter, characteristic function, noise immunity, signal-to-noise ratio, amplitude manipulation. DOI: 10.25791/pribor.12.2019.1063 Contacts: - Pp. 36-42.