Performance of Reconfigurable Intelligent Surfaces vs. Relaying for UAV-Assisted Communications

Reconfigurable intelligent surfaces (RIS) have been recently proposed as an emerging technology to enhance wireless coverage. In this paper, we examine the performance of RIS-enabled unmanned aerial vehicle (UAV)-assisted communications in comparison with decode-and-forward (DF) relaying. Our results quantify the number of RIS elements required to outperform DF relaying in terms of the achievable rate. Additionally, we demonstrate effect of the UAV height on the total transmit power.