Directional macro-cell channel characterization from urban measurements

We measured the angular power distribution at the mobile station in downtown Paris at 890 MHz. The transmit antenna was omnidirectional and placed high above rooftops. The receiver antenna, a 21×41 element rectangular synthetic array, was located on the roof of a van. The refined high-resolution evaluation method, particularly robust against nonstationary signal components, allows an angular resolution of better than 1° in both azimuth and elevation and a delay resolution of 33 ns. Combined angular/temporal domain measurements are crucial for the understanding of the propagation mechanisms. The evaluated sites showed strongly street-dominated propagation. We found a combined circular and rectangular distribution of scatterers around the mobile station in street-dominated environments. Propagation over the roofs was significant; typically 65% of energy was incident with elevation larger than 100. Our results corroborate the hypothesis on the importance of multiple reflections/diffractions in urban macro cells. We explain this behavior by two reasons: narrow streets favoring a canyon effect and strong scatterers without line-of-sight (LOS) to the mobile station