Performance of mmWave Ray Tracing Outdoor Channel Model Exploiting Antenna Directionality

The millimeter (mmWave) 5G new radio (NR) aims to provide orders of magnitude greater capacity through increased bandwidth and beamforming assisted narrow beam transmissions. The assumption of directional antennas with narrow radiating beams will reduce the number of contributing multipaths causing the channel to be sparser and simpler than the omnidirectional microwave channel. In this paper, we used a custom ray tracing model to study the behavior of directional mmWave urban micro (UMi) street canyon (SC) links. The proposed channel model harnesses the higher attenuation in high frequency mmWaves and the spatial filtering of directional antennas to reduce ray tracing complexity. The potential of this low complexity model has been evaluated through comprehensive simulation for both line of sight and non-line of sight mmWave communications at ranges up to 200m with different transmitter and receiver geometries. The impact of crossroad gaps on channel performance in a real urban SC 5G outdoor network design is also formulated. Several interesting insights have been derived. The strength of the proposed model constitutes path loss predictions at varying positions, frequency, and street orientation with/ without sidewall discontinuities.