Data Rate Maximization in IRS-Aided Downlink with Effective Positioning

Next-generation technologies aim to achieve highly efficient communication systems in the evolving wireless communication landscape. Among these, intelligent reflective surfaces (IRS) are expected to play a pivotal role. IRS comprises multiple reflective elements that act as phase shifters, reflecting signals transmitted from the access point (AP). The positioning of the IRS is crucial in determining system performance. This paper evaluates the data rate performance by varying the projection position of the IRS between the AP and user equipment (UE). The optimal phase shifters achieve gains of ~3.353 bps/Hz and ~3.374 bps/Hz compared to random phase shifters at the AP and UE, respectively. Additionally, when near the AP and UE, they provide gains of ~3.187 bps/Hz and ~3.246 bps/Hz, respectively, over discrete phase shifters with <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$n$</tex> = 4. Simulation results validate the enhanced performance, demonstrating the effectiveness of optimal IRS positioning and phase shifting in boosting overall system throughput.