Terahertz (THz) multiuser massive multiple-input multiple-output (MIMO) has been envisioned as a promising technique to support massive connectivity in next-generation wireless networks. However, due to ultra-high frequency band, the path attenuation of THz channels is extremely severe, resulting in limited wireless coverage. In this paper, we propose an intelligent reflecting surface (IRS)-assisted THz multiuser massive MIMO technique to enhance coverage. First, we design an IRS-assisted THz communication framework with a low-cost sub-connected hybrid precoding architecture, including uplink data transmission and downlink data transmission. In particular, precoding errors due to the limitations of physical devices and environments are taken into consideration. Then, we derive the closed-form expressions for uplink and downlink spectral efficiencies, and reveal the impacts of system parameters. Finally, we conduct extensive simulations to verify the effectiveness of the proposed IRS-assisted THz multiuser massive MIMO technique.

太赫兹 (THz) 多用户大规模多输入多输出 (MIMO) 已被视为支持下一代无线网络大规模连接的有前途的技术。然而，由于超高频段，太赫兹信道的路径衰减极其严重，导致无线覆盖范围有限。在本文中，我们提出了一种智能反射面 (IRS) 辅助的太赫兹多用户大规模 MIMO 技术来增强覆盖范围。首先，我们设计了一个具有低成本子连接混合预编码架构的IRS辅助太赫兹通信框架，包括上行数据传输和下行数据传输。特别是考虑了由于物理设备和环境的限制导致的预编码错误。然后，我们推导出上行链路和下行链路频谱效率的闭式表达式，并揭示系统参数的影响。最后，我们进行了广泛的模拟，以验证所提出的 IRS 辅助太赫兹多用户大规模 MIMO 技术的有效性。