Time-varying K factor of the mm-Wave vehicular channel: Velocity, vibrations and the road quality influence

This paper evaluates real-world intra-vehicle millimeter-wave (mmWave) channel measurements performed in a vehicular environment. Utilizing a correlative time-domain channel sounder, we demonstrate the dependency of the time-varying Rician K factor on the road quality and instantaneous velocity of the measured vehicle. Vibrations caused by the movement of the vehicle together with mechanical properties of the vehicle's chassis leads to a mutual movement of the transmitting (TX) and the receiving (RX) antennas mounted on the front windshield and on the rear quarter window respectively. The channel sounding is performed in a frequency bandwidth from 59.1GHz to 64 GHz with 50GS/s sampling frequency.