Millimetric wavelengths radiowave propagation for line-of-sight indoor microcellular mobile communications

Discusses millimeter waves for indoor microcellular communications. The results of propagation experiments conducted at 60.4 GHz (the oxygen absorption band) and 38.25 GHz to determine multipath characteristics in a number of indoor microcell channels employing omnidirectional antennas are presented. Cumulative distribution functions for received signal envelope, as well as corresponding power spectra are given. In addition, a comparison between the fading statistics measured at 60.4 GHz and 38.25 GHz under similar conditions is made. The change in multipath characteristics due to the presence of different building materials is also illustrated. A ray model is developed to represent indoor microcell propagation by considering a direct ray plus rays which have undergone single and double reflections from the walls. Specular floor-reflected and ceiling-reflected rays are included when the antennas radiation pattern does not preclude them. Using this simple model, the signal variations and the amplitude of reflected rays with respect to the line of sight (LOS) ray as functions of mobile receiver position are predicted and used to assist in interpreting experimental results. Theoretical results are found to be in good agreement with measured ones, with the model also being used to predict structure-induced root mean square (rms) delay spread along receiver routes in an indoor microcell environment. This parameter is a measure of multipath conditions in a mobile radio channel and is inversely proportional to the maximum usable data signalling rate of a channel.<
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