6-D Deployment Optimization for Intelligent Reflecting Surface-Aided Wireless Communication

In this letter, we propose a new intelligent reflecting surface (IRS)-aided communication system, where an IRS with directional gain pattern is flexibly positioned/rotated to aid the communication from a user to an access point (AP). Specifically, we aim to maximize the received signal-to-noise ratio (SNR) at the AP, by jointly optimizing the six-dimensional (6D) deployment of the IRS, i.e., its three-dimensional (3D) positions and 3D rotations. To solve this problem, we propose an efficient alternating optimization (AO)-based algorithm by first decoupling it into two subproblems: 1) the IRS’s 3D position optimization and 2) the IRS’s 3D rotation optimization, and then alternately solving each subproblem until satisfying a given convergence condition. Our simulation results show that the proposed system can significantly improve the communication performance, as compared to the benchmark IRS architectures with fixed-position elements (FPEs) or IRS with position/rotation optimization only.