Enhancing UAV-Enabled Communications via Multiple Intelligent Omni-Surfaces

This letter investigates an air-ground communication system where an unmanned aerial vehicle (UAV) communicates with multiple users with the assistance of multiple intelligent omni-surfaces (IOSs). Our goal is to maximize the minimum average expectation of the achievable rate through the joint optimization of the users' scheduling, IOSs' phase shifts, and UAV's trajectory. We first show the random channel power gains follow the more tractable noncentral Chi-square distribution. Then, the resulting optimization problem is a mixed-integer non-convex problem with tightly coupled optimization variables, which is difficult to solve optimally. We propose an efficient algorithm to obtain the suboptimal solution based on block coordinate descent (BCD) and successive convex approximation (SCA) methods. Simulation results show that our proposed scheme significantly outperforms other benchmark schemes.