**5. Conclusion**

The carried out analysis shows that in channels with random parameters (channels of systems of mobile communication, channels of tropospheric and ionospheric radio propagation, etc.) when the admissible time delay of signals exceeds duration of time intervals in which the relation a signal/noise becomes inadmissible small, application of principles of intermittent communication allows to obtain the considerable gain in noise immunity. The magnification of gain is connected to lowering of spectral efficiency and magnification of delay period of signals.

For saving of average rate of information transfer it is necessary to increase the instant speed and by that to expand occupied frequency band under a condition when in the modem communication systems basic is the requirement of saving of the frequency resource.

The analysis usage complexation of intermittent communication and diversity reception allows not only to lower probability of error an accepted signal, but also sharply to raise use factor of radio-line (spectral efficiency), especially at complexation of diversity reception

with the intermittent communication which is carried out on an output of the circuit of optimal addition. The magnification of spectral efficiency is very significant owing to limitation of a resource of an electromagnetic spectrum.

The analytical ratios obtained in the given chapter, show, what gain can be implemented at usage methods of intermittent communication in various situations at the various statistics fading amplitudes of signals. These ratios allow calculating also probabilities of error at a fading of signals under laws of Rayleigh, Rice (generalized Rayleigh), Nakagami, and also lognormal laws at incoherent and coherent receptions.

In cases of possible applications for the mode of intermittent radiation (i.e., turn off the transmitter at low signal levels), the most complete communication channel can be used in a combination of variable speed and intermittent modes of communication. Potential possibilities usage methods of intermittent communication especially in a combination to other known methods of increase of noise immunity are considerable.

One of main limitation of method of intermittent communication is necessity of the considerable time delays of signals. In connection with electronics achievements this lack has the lesser value. Mastering of more and more high-frequency ranges of radio-waves leads to possibility to reduce delay period in equipment of these ranges (speed of a fading above). In connection with the marked circumstances it is possible to assume that interest to usage of methods of intermittent communication will increase.

By this time research of systems from intermittent communication is led insufficiently full. The authors suggest investigating these systems under the influence of fading interference from other radiation sources (for example, in the case Rayleigh fading as a useful signal and noise). Researches influence correlations of a fading signal in reception branches are necessary. As different variants of complex application of intermittent communication and diversity of signals (circuits **MIMO)** are possible, it is supposed to conduct similar researches for other variants of combined usage of intermittent communication and diversity of signals, for example at usage of different levels of thresholds at interruption's realization in different branches of diversity. Usage of intermittent communication when the signal envelope suffers simultaneously some types of a fading is of interest. For example, at propagation of signal in millimeter range through troposphere, a fading of its envelope is carried out simultaneously under laws lognormal and Nakagami. Probability density fading envelope of signal as the special case of a fading discussed (when the signal envelope fluctuates simultaneously under laws Rayleigh and lognormal and under laws Rice and lognormal) has been obtained accordingly Suzuki and Patzold in 1977 and 1998.
