Methodology for Evaluating the Probability of Communication Disconnection in Radio Channels of the Systems with Space-Time Coding of Signal

The paper presents a methodology for assessing the probability of communication disruptions in one beam of a radio communication system operating on the technology of space-time coding of signals. Expressions are given for an accurate and for an approximate estimate of the probability of communication disruptions in radio channels with multipath and signal fading. Long-term experimental studies of signal fading on a long-range tropospheric radio link have been carried out. It has been experimentally proven that the Rayleigh description of interference fading in multipath propagation of signals is observed in 60% of the time of communication sessions. For the rest of the communication sessions, other laws of probability distribution are observed. It is confirmed that they, together with Rayleigh's description of fading, are special cases of the four-parameter law of probability distribution. Convenient for practical use formulas are obtained for estimating the noise immunity of a communication channel. The graphs of the dependence of the probability of communication failure on the ratio of the average received signal power and the threshold level of the receiver signal are given.