Exploiting Beam-Split Effect in IRS-Aided Systems via Opportunistic OFDMA: Design and Analysis

This paper addresses the challenges caused by employing phased-array-based intelligent reflecting surfaces (IRSs) for wideband beamforming applications at mmWave frequencies. When a large IRS is used in conjunction with a wideband signal, a phenomenon known as the beam-split (B-SP) effect arises wherein the IRS fails to focus its reflected energy toward a single user equipment (UE) across the entire signal bandwidth, resulting in a dramatic reduction in array gain and throughput. While B-SP is c