Basestation 3-dimensional spatial propagation characteristics in urban microcell at 28 GHz

This paper presents a millimeter wave channel measurement in Urban Microcell (UMi) scenario at 28 GHz with a bandwidth of 400 MHz. During measuring, a steerable horn antenna is used at receiver (RX) side while an omnidirectional antenna is used at transmitter (TX) side. The horn antenna not only rotates in azimuth with a step of 5° but also points into three different vertical angles. Based on the measured data, the 3-dimensional (3D) space characteristics of the millimeter wave channel are analyzed at the basestation (BS) side, e.g., azimuth angular spread of arrival (AASA), elevation angular spread of arrival (EASA) and their clustering results, by using the Space-Alternating Generalized Expectation-maximization (SAGE) algorithm and KPowerMeans algorithm. Through comparing the power angular profiles (PAPs) of raw data (RD) and SAGE results, the dynamic range of SAGE results will increase. The positive correlation between the measured distance and EASA is also investigated here.