Mitigating Channel Aging and Phase Noise in Millimeter Wave MIMO Systems

We consider non-stationary and time-varying millimeter wave (mmWave) communication systems subjected to phase noise at both transmitter and receiver. Our aim is to compensate for practical imperfections in high-mobility scenarios, such as vehicle-to-everything (V2X). To this end, an analytical expression of the mean square error (MSE) performance of the data transmission in mmWave communication systems is derived, taking into account both phase noise disturbance and time-varying effects modeled via a first-order auto-regressive (AR) model. Building on the latter result, a convergent minimum mean square error (MMSE) beamforming algorithm is then proposed, which is shown via simulations to outperform state-of-the-art beamforming methods designed to optimize MMSE as well as rate-maximization design criteria.