Number and duration of fades at 6 and 4 Ghz

We present in this paper experimental and theoretical results on the number of fades, average durations of fades, and the probability distributions of fade durations for line-of-sight microwave transmission in the 6- and 4-GHz bands. Both fading of single signals and simultaneous fading of pairs of signals within each of the two bands are treated. The experimental results are based on data obtained in 1966 in Ohio. Mathematical description of the number and average duration of fades is based on a theory in which pairs of signals are treated as correlated random variables that are jointly Rayleigh distributed. The durations of deep fades of single signals tend to be lognormally distributed. A probability distribution of the duration of simultaneous fades, which agrees with experimental data, is obtained from the lognormal distribution using a heuristic model.