An improvement to hybrid beamforming precoding scheme for mmWave massive MIMO systems based on channel matrix

The massive multiple-input multiple-output (MIMO) technology has been applied in new generation wireless systems due to growing demand for reliability and high data rate. Hybrid beamforming architectures in both receiver and transmitter, including analog and digital precoders, play a significant role in 5G communication networks and have recently attracted a lot of attention. In this paper, we propose a simple and effective beamforming precoder approach for mmWave massive MIMO systems. We first solve an optimization problem by a simplification subject, and in the second step, we use the covariance channel matrix fCk =Cov(Hk) and Bk = HkHHk instead of channel matrix Hk. Simulation results verify that the proposed scheme can enjoy a higher sum rate and energy efficiency than previous methods such as spatially sparse method, analog method, and conventional hybrid method even with inaccurate Channel State Information (CSI). Percentage difference of the achievable rate of Ck = Cov(Hk) and Bk = HkHHk schemes compared to conventional methods are 2.51% and 48.94%, respectively