Automated UWB-Based Phased Array Channel Sounding for the 28 GHz mmWave Band

Localization and sensing are key features of future 5G and 6G wireless communication networks. To develop these functionalities, high-performance channel sounding is required. This work proposes an automated ultra-wideband (UWB) phased array channel sounder for the 28 GHz mmWave band. The system design and implementation of the channel sounder are presented. It is based on commercially available mmWave phased array antennas with up/down (U/D) converters as frontends and a UWB channel sounder as an intermediate frequency (IF) unit. Post-processing was applied to remove interfering measurement artifacts. The entire measurement setup was verified with an appropriate two-path model. Also, the dynamic range (DR) was checked. After verification, measurement campaigns were conducted to characterize the spatial propagation properties of an indoor laboratory. The results emphasize the need for beam steering and efficient beam management in mmWave systems to compensate for strongly varying path power levels inside a room.