Random beamforming combined with receive beamforming in mmWave multiuser MIMO downlink

The performance of transmit random beamforming (RBF) with receive beamforming at each user is investigated for millimeter wave (mmWave) multiuser multiple-input multiple-output (MU-MIMO) downlink systems. It is shown that RBF in MU-MIMO systems with the total transmit power inversely proportional to the number of receive antennas can achieve the performance of the conventional RBF scheme with the constant total transmit power in MU multiple-input single-output (MISO) systems with no receive beamforming, when the number of transmit antennas is large.