论文标题
可重新配置的智能表面辅助多用户通信：我们需要多少个反射元素？
Reconfigurable Intelligent Surface assisted Multi-user Communications: How Many Reflective Elements Do We Need?
论文作者
论文摘要
由多个反射元素组成的可重构智能表面（RISS）是一种有前途的技术，可以增强沟通质量，因为它们可以创造出良好的传播条件。在这封信中，我们表征了反射元素数量与RIS辅助多用户通信中的系统总和率之间的基本关系。从以前的作品中知道，接收到的信噪比〜（SNR）可以随着RIS反射元素的平方数量而线性增加，但是有多少个元素足以提供可接受的系统总和仍然是一个空旷的问题。为此，我们以零强化（ZF）的预编码得出渐近能力，然后讨论需要多少反射元件，以使系统总和率与容量的比率可以超过预定义的阈值。数值结果验证了我们的分析。
Reconfigurable intelligent surfaces (RISs) consisting of multiple reflective elements are a promising technique to enhance communication quality as they can create favorable propagation conditions. In this letter, we characterize the fundamental relations between the number of reflective elements and the system sum-rate in RIS-assisted multi-user communications. It is known from previous works that the received signal-to-noise ratio~(SNR) can linearly increase with the squared number of RIS reflective elements, but how many elements are sufficient to provide an acceptable system sum-rate still remains an open problem. To this end, we derive the asymptotic capacity with zero-forcing (ZF) precoding, and then discuss how many reflective elements are required so that the ratio of the system sum-rate to the capacity can exceed a predefined threshold. Numerical results verify our analysis.
