Radio propagation at microwave frequencies for line-of-sight microcellular mobile and personal communications

A propagation experiment has been designed and conducted at 900 MHz and 11 GHz to characterize microcell channels using various antennas at two distinct frequencies. It is found that propagation in rural areas is dominated by interference between the direct, line-of-sight ray and a specular roadway-reflected ray. In urban areas, the addition of four specular wall-reflected rays adequately represents microcell propagation. The dependence of mean power falloff, measured mean power and calculated power on distance was determined. The lambda /2 scale microvariations of the received power are reduced compared to the variations in present cellular radio systems. For urban sites using omnidirectional base and mobile antennas, the RMS delay spread due to road- and wall-reflected rays was obtained from a six-ray model. Using a 20-dB horn for the mobile antenna can reduce this delay spread.<
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