Directional delay spread characteristics based on indoor channel measurements at 28GHz

Millimeter-wave propagation characteristics and channel models are being recently studied for applicability of the fifth generation (5G) mobile communication systems. To overcome the larger path loss on the higher frequency band above 6 GHz, 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 channel measurement campaign is introduced which makes use of a direction-scanning-sounding technique to study channel characteristics of 28 GHz millimeter-wave propagation in indoor environments. The measurement campaign has been conducted in passenger terminals at Seoul Railway Station and Incheon International Airport, which are representative indoor hotspot regions in Korea. Based on our experimental data, we investigate the relationship between the beamwidth of antenna and r.m.s. delay spread characteristics.