  Millimeter wave (mmWave) bands have been utilized for the fifth generation
(5G) communication systems and will no doubt continue to be deployed for beyond
5G (B5G). However, the underlying channels are not fully investigated at
multifrequency bands and in multi-scenarios by using the same channel sounder,
especially for the outdoor, multiple-input multiple-output (MIMO), and
vehicle-to-vehicle (V2V) conditions. In this paper, we conduct multi-frequency
multi-scenario mmWave MIMO channel measurements with 4*4 antennas at 28, 32,
and 39 GHz bands for three cases, i.e., the human body and vehicle blockage
measurements, outdoor path loss measurements, and V2V measurements. The channel
characteristics, including blockage effect, path loss and coverage range, and
non-stationarity and spatial consistency, are thoroughly studied. The blockage
model, path loss model, and time-varying channel model are proposed for mmWave
MIMO channels. The channel measurement and modeling results will be of great
importance for further mmWave communication system deployments in indoor
hotspot, outdoor, and vehicular network scenarios for B5G.
