Performance analysis of active IRS-assisted 5 G/6 G wireless communications networks

The rapid growth of mobile technologies has increased the demand for high-speed, reliable, and energy-efficient wireless communication systems for B5G and 6 G networks. Although passive intelligent reflecting surfaces (IRSs) improve wireless coverage and spectral efficiency (SE), they suffer from limited coverage extension, signal attenuation, and the lack of amplification capability. This work investigates an active IRS-assisted multi-user wireless communication system in which IRS elements amplify incident signals through integrated active components. An active IRS signal model considering amplification noise and self-interference effects is developed under Rician fading channels. An alternating optimization (AO) framework is adopted to jointly optimize beamforming and IRS reflection coefficients to improve wireless coverage and energy efficiency (EE). Simulation results demonstrate that the proposed active IRS significantly outperforms passive IRS and without-IRS schemes under both weak-link and strong-link conditions. In the weak-link scenario at \\(L = 100~\\textrm{m}\\) , the active IRS improves EE by approximately \\(20\\%\\) and \\(60\\%\\) compared to passive IRS and without-IRS schemes, respectively, while achieving nearly 30 bits/Joule at \\(P_t = 30~\\textrm{dBm}\\) . In the strong-link scenario, the active IRS provides approximately \\(23\\%\\) and \\(78\\%\\) higher EE than passive IRS and without-IRS schemes, respectively, achieving approximately 35 bits/Joule compared to 20 and 18 bits/Joule. These results confirm that active IRS effectively mitigates fading, enhances energy efficiency, extends wireless coverage, and improves interference management, highlighting its strong potential for energy-efficient B5G and 6 G wireless communication systems.