Channel Feasibility for Outdoor Non-Line-of-Sight mmWave Mobile Communication

Channel Models and Beamforming at Millimeter-Wave Frequency Bands

“…[70] reports angular spreads of an indoor NLOS channel for different Tx and Rx antenna polarizations, showing that they vary about ±40% and ±10% around the median value on the azimuth and elevation domains, respectively. The angular spread values in outdoor cellular scenarios are presently lacking, though there have been several measurements that allow for them, e.g., [24], [28], [71].…”

“…The indoor channel sounding [70] shows clear clustering of multipaths according to the PAS and power angular-delay profiles. In contrast, there are also works reporting PAS spread over wide angular range; [71] shows PAS of outdoor rooftop-to-ground channels at 28 GHz, revealing rich scattering even in LOS cases. The work [90] reports that radio channels in large indoor scenarios at 60 and 70 GHz show a uniform distribution of propagation paths over the azimuth angle, and that the path clustering phenomenon is not prevailing over the spatio-temporal domain.…”

“…Though the diffuse scattering is popularly reported at the microwave frequencies, e.g., [91], where the roughness of the scatterers are comparable to the wavelength, there is no consensus if the scattering is more dominant at the mm-wave or not since there are plenty of physical objects whose roughness is on the order of millimeter, e.g., brick walls [127] and small items on a desktop [71]. Scattering at mm-wave band has been reported in [152] through reflection coefficient measurements on cement walls with different surface roughness profiles at 28 and 38 GHz.…”

“…The use of less-directive antennas is suggested in [47] to increase the link availability in timevarying channels due to human movement in indoor office. For outdoor cellular scenarios, [71] indicates that an antenna with wide beamwidth at a ground level may lead to robust link budget in their rooftop-to-ground channel at 28 GHz, given the rich scattering and lack of beam tracking at the rooftop. Flattening antenna beams is proposed in [163] to cope with small variations of directional antenna orientation incurred by wind for mast-mounted outdoor backhaul links.…”

Interference Modeling for Cellular Networks Under Beamforming Transmission

“…The current scarcity of wireless spectrum coupled with the predicted exponential increase in capacity demand has focused attention on denser network deployment and the underutilized millimeter wave (mmWave) bands (30-300 GHz) [1]- [3]. Fifth generation (5G) wireless systems aiming to cater for the capacity demand are expected to provide a minimum of 1 Gb/s data rate anywhere with up to 5 Gb/s for high mobility users and 50 Gb/s data rates for pedestrians [2].…”