Low Complexity Hybrid Precoding Algorithm for THz Ultra-massive MIMO Systems

The hybrid precoding problem in point-to-point TeraHertz (THz) multiple-input multiple-output (MIMO) systems can be solved by minimizing the Frobenius norm between the digital precoder and the hybrid precoder. To achieve this, we developed an alternating minimization algorithm, the MBCD-HP for mmWave massive MIMO systems. However, the complexity can be very high when the number of antennas increases, as required in THz transmission. In this paper, we improve MBCD-HP algorithm by utilizing the structural properties of the optimization matrix. The simulation results demonstrate that the proposed method significantly reduces the computational complexity and improves the performance.