Millimeter-Wave 60 GHz Outdoor and Vehicle AOA Propagation Measurements Using a Broadband Channel Sounder

Millimeter wave (mm-wave) channel models for outdoor wireless systems with adaptive antennas are needed to exploit the massive bandwidths available at frequencies above 30 GHz. In this paper, we describe 60 GHz wideband propagation measurements in cellular peer-to-peer outdoor environments and in-vehicle scenarios. We present a channel sounder that operates at 38 and 60 GHz with a passband bandwidth of 1.9 GHz. The channel sounder provides sub-ns RMS delay spread measurement resolution and angle-of-arrival (AOA) capabilities. AOA multipath measurements for cellular peer-to-peer communications in an outdoor campus setting show that in all measured locations, some non-Line of Sight (NLOS) antenna orientations can exploit beamforming to create links using scattering in the channel. Measurements using rotating directional antennas in NLOS antenna pointing scenarios found links with up to 36.6 ns RMS delay spread and an average propagation path loss exponent of 4.19, whereas LOS channels provided sub-nanosecond RMS delay spreads and an average path loss exponent of 2.23 (close to free space). Measurements into a vehicle showed similarities to outdoor peer-to-peer environments for LOS channels, but in NLOS situations there was significantly greater path attenuation due to the vehicle interior, vehicle body, windows, and passengers in the vehicle.