Opportunistic Beamforming Using an Intelligent Reflecting Surface Without Instantaneous CSI

While intelligent reflecting surface (IRS) assisted wireless communication has emerged as an important research paradigm, channel state information (CSI) acquisition remains a critical challenge to design the IRS phase-shifts and yield promised coherent beamforming gains. In this letter, we propose IRS-assisted opportunistic (OBF) scheme under proportional fair scheduling, which does not require instantaneous CSI parameters. slow-fading environment, show that with only random rotations at IRS, proposed can capitalize on multi-user (MU)-diversity effect approach performance of number users grows large. Next study sum-rate scaling OBF in correlated Rayleigh fast fading environment deterministic results considerable improvement.