Wideband hybrid precoding for THz massive MIMO with angular spread

Terahertz (THz) wideband hybrid precoding is a promising technology for enabling Tbps transmission in 6G massive multiple-input-multiple-output (MIMO) systems. Despite the abundant spectrum resources, a severe beam-split effect will be induced in THz massive MIMO communications, degrading the system capacity. The existing THz wideband precoding schemes mainly focus on overcoming the beam-split effect in line-of-sight (LOS) scenarios but cannot cope with the beam-split effect in non-LOS (NLOS) scenarios in the presence of angular spread. To address this issue, we first analyzed and compared the differences in the beam-split effect in LOS and NLOS scenarios. Then, a delay-time joint optimization algorithm is proposed to mitigate the beam-split effect in NLOS scenarios. Finally, simulations were conducted to verify the effectiveness of the proposed method.