Performance Analysis of Active IRS-Aided MU-MISO System

With advancements in signal propagation and coverage enhancement technologies, Intelligent Reflecting Surfaces (IRS) have emerged as a transformative solution for future wireless communication systems beyond 5G and 6G. While passive IRS has been extensively explored, active IRS has recently attracted attention due to its capability to amplify reflected signals rather than merely redirecting them, thereby mitigating the detrimental effects of multiplicative fading. In this study, we analyze an active IRS-assisted multi-user multiple-input single-output (MU-MISO) system operating under weak line-of-sight (LoS) conditions. The investigation focuses on the impact of ideal and practical phase shift models on the overall system performance, particularly with respect to sum-rate maximization. Key system parameters, including the distance between the base station (BS) and users, total transmit power, and the number of IRS elements, are considered in the analysis. Furthermore, the study evaluates the energy efficiency of active IRS-assisted systems under varying levels of phase quantization and total power consumption. Our findings provide critical insights into the trade-offs between active IRS-assisted and conventional non-IRS systems, highlighting the practical implications of deploying active IRS in real-world scenarios. This work aims to bridge the gap between theoretical advancements and practical deployment, thereby contributing to the development of more efficient IRS-assisted wireless networks.