Achievable Rate Optimization for Aerial Intelligent Reflecting Surface-Aided Cell-Free Massive MIMO System

The intelligent reflecting surface (IRS) is considered a core technology of next-generation mobile communication. It has significant advantages in enhancing network coverage, spectrum efficiency, energy and deployment cost. Compared with the conventional massive multiple-input-multiple-output (MIMO) system, cell-free MIMO overcomes limitation imposed by inter-cell interference traditional cellular networks realizes coherent transmission centered on users. In this article, we consider new application scenario for IRS - an aerial (AIRS)-aided system where multiple APs serve several users through AIRS. are “shadow area” cannot provide good quality service (QoS) due to remote location shelter tall buildings. Our goal optimize power allocation beamforming each AP, placement reflection phase shift parameters AIRS maximize user's achievable rate. Firstly, optimization fixed AIRS, propose joint strategy rate user. Then, fast optimal search algorithm base path loss model determine decrease computational complexity. simulation results show that proposed methods can improve performance system. To best our knowledge, article first study combination