Specificity of signals reception in digital radio channels of the millimetric wave band

The primary goals at creation of communication channels is to provide the specified data rate. In order to maximize the accuracy of data transmission, one can use the methods for optimal reception of discrete signals. In long-wave bands the noise source is thermal floataions in the receiving apparatus, as well as signals distortion. Thus the propagation medium (atmosphere) is supposed to be ideal, i.e. it is noiseless, lossless and undistorting. In order to provide optimal reception of discrete signals it is sufficient to know their a priori thin signal structure. However in millimeter band the Earth atmosphere possesses dispersion properties, which are sufficiently changing because of the weather. Due to this fact it is necessary to know the changes of thin structure under the influence of atmosphere.