Channel Characteristics for 5G Wireless Systems Operating in Millimeter-wave Bands

Co-located 4 x 4 multiple-input multiple-output measurements of link gain, delay spread, and capacity at 24 GHz and 2.55 GHz are compared for an indoor environment consisting of offices, large rooms, and hallways. The results show that link gain at the two frequencies is similar in hallways and connected laboratories after removing the impact of effective antenna aperture but is much lower at 24 GHz in non-line-of-sight scenarios. For all environments, median delay spreads as well as system capacity at a fixed signal-to-noise ratio at 24 GHz are similar to those observed at 2.55 GHz. Ray tracing simulation results show reasonable to good agreement with the measured link gain but tend to provide lower capacity estimates. Overall, the results suggest that bands near 24 GHz may be able to support multiple-antenna communication strategies.