Reconfigurable Intelligent Surfaces (RIS) are planar structures connected to electronic circuitry, which can be employed to steer the electromagnetic signals in a controlled manner. Through this, the signal quality and the effective data rate can be substantially improved. While the benefits of RIS-assisted wireless communications have been investigated for various scenarios, some aspects of the network design, such as coverage, optimal placement of RIS, etc., often require complex optimization and numerical simulations, since the achievable effective rate is difficult to predict. This problem becomes even more difficult in the presence of phase estimation errors or location uncertainty, which can lead to substantial performance degradation if neglected. Considering randomly distributed receivers within a ring-shaped RIS-assisted wireless network, this paper mainly investigates the effective rate by taking into account the above-mentioned impairments. Furthermore, exact closed-form expressions for the effective rate are derived in terms of Meijer's $G$-function, which (i) reveals that the location and phase estimation uncertainty should be well considered in the deployment of RIS in wireless networks; and (ii) facilitates future network design and performance prediction.
翻译:重新配置的智能表面(RIS)是连接到电子电路的平板结构,可以用来控制电磁信号。通过这种结构,信号质量和有效数据率可以大大改进。虽然已经对各种情况调查了RIS辅助无线通信的好处,但网络设计的某些方面,如RIS的覆盖范围、最佳位置等,往往需要复杂的优化和数字模拟,因为可实现的有效率难以预测。在出现阶段估计错误或位置不确定性的情况下,这一问题变得更加困难,如果忽视,可能导致性能严重退化。考虑到在环形的RIS辅助无线网络中随机分布接收器,本文件主要调查有效率,同时考虑到上述缺陷。此外,Meijer的$G美元功能是有效率的精确封闭式表达方式,这(一)表明在无线网络部署RIS时应该很好地考虑位置和阶段估计不确定性;以及(二)便利未来网络设计和性能预测。