The transition to Terahertz (THz) frequencies, providing an ultra-wide bandwidth, is a key driver for future wireless communication networks. However, the specific properties of the THz channel, such as severe path loss and vulnerability to blockage, pose a significant challenge in balancing data rate and reliability. This work considers reconfigurable intelligent surface (RIS)-aided THz communication, where the effective exploitation of a strong, but intermittent line-of-sight (LOS) path versus a reliable, yet weaker RIS-path is studied. We introduce a mixed-criticality superposition coding scheme that addresses this tradeoff from a data significance perspective. The results show that the proposed scheme enables reliable transmission for a portion of high-criticality data without significantly impacting the overall achievable sum rate and queuing delay. Additionally, we gain insights into how the LOS blockage probability and the channel gain of the RIS-link influence the rate performance of our scheme.

翻译：向太赫兹（THz）频段过渡可提供超宽带宽，这是未来无线通信网络的关键驱动力。然而，太赫兹信道的特有属性，例如严重的路径损耗和易受阻挡的脆弱性，给数据速率与可靠性之间的平衡带来了重大挑战。本文研究了可重构智能表面（RIS）辅助的太赫兹通信，探讨如何有效利用一条强但间歇性的视距（LOS）路径与一条可靠但较弱的RIS路径之间的权衡。我们提出了一种混合关键性叠加编码方案，从数据重要性的角度解决这一权衡问题。结果表明，所提方案能够在不显著影响整体可实现总速率和排队时延的前提下，为部分高关键性数据实现可靠传输。此外，我们深入分析了LOS阻挡概率和RIS链路信道增益对该方案速率性能的影响。