Intelligent Reflective Surface Aided Multi-Way Communications

In this paper, an intelligent reflective surface (IRS)-aided multi-way communication system is investigated. The full-duplex reflective properties of the IRS are exploited to enable full-mutual data exchange among multiple users within a single channel-use. A max-min fairness-based achievable rate optimization problem is formulated to control the phase-shift matrix at the IRS. To this end, a minorization-maximization based iterative IRS phase-shift optimization algorithm is used to maximize the minimum achievable system-wide user rate. The simulation/numerical results are presented to validate the convergence of the proposed IRS phase-shift optimization algorithm and to investigate the system performance. Thereby, it is revealed that the proposed system mitigates the adverse near-far effects by ensuring a common system-wide achievable user rate while accomplishing full-mutual data exchange via intelligently controlling the phase-shifts at the IRS. Our numerical results reveal that the proposed system outperforms the current stateof-the-art multi-way communication system based on multipleinput multiple-output (MIMO) relays in terms of the achievable sum rate in the moderate-to-large IRS element regime.