Polarization diversity for urban millimetric mobile radio communications: comparison of initial propagation measurement results with prediction

An experimental study of the propagation of vertical and horizontal polarized 55-GHz millimeter waves from a fixed transmitter to a mobile receiver in an urban environment is described. Ranges up to 400 m were used and measurements were obtained in the presence of traffic. Components transmitted received on orthogonal polarizations are uncorrelated. Cross coupling components are on average 10-20 dB lower than co-coupling components and are also uncorrelated. Low cross-polarization levels suggest that propagation is dominated by interference between the direct line-of-sight (LOS) path and specular reflections from the road surface and sides of the street. Similarity of experiment results with prediction of a simple vector model of the direct path and principle specular reflections also supports this observation. At very close range, when the received signal is dominated by LOS propagation, the highest measured correlation is 0.47