Near-Field Beamforming and Doppler Compensation for mmWave Internet of Vehicles

This letter considers the near-field beamforming in millimeter wave Internet-of-vehicle, where phased arrays have been widely used for mitigating misfocus effect. In near-field regime, the angle and distance need to be considered simultaneously due to the fact that the wave propagation is spherical. We design the phase profile of the antenna arrays by using the angle and distance information to meet characteristic of near-field spherical wavefront. Then, we construct the chirp signal based on the hybrid frequency modulation technique to improve Doppler sensitivity to compensate the effect caused by the movement of the vehicles. Our results reveal that the proposed method can achieve high data rates by reducing the beam misfocus and Doppler effect in millimeter wave Internet-of-vehicle.