Directional multipath propagation characteristics based on 28GHz outdoor channel measurements

Propagation characteristics of millimeter-wave are being widely studied for utilization of the fifth generation (5G) mobile communication systems. To overcome the severe path loss on the high frequency band, highly directive antennas or beamforming techniques using large array antennas can be used to establish a reliable communication link between a transmitter and a receiver. In this paper, a recently conducted outdoor channel measurement using directional horn antenna in the 28GHz frequency band is introduced. The measurement campaign has been conducted in typical urban low-rise and very high-rise environments in Korea. To investigate directional multipath characteristics, large-scale parameters such as root mean square (RMS) delay spread and angular spread of arrival corresponding to the beamwidth of antenna are extracted. Finally, we derived empirical models based on our measurement results to estimate these large-scale parameters.