Sum Throughput Maximization for IRS-Aided Wireless-Powered D2D Communication Systems

Device-to-device (D2D) communication allows direct device interactions but is limited by signal attenuation, interference, and energy constraints. Integrating intelligent reflecting surfaces (IRSs) and wireless-powered communication networks (WPCNs) enhances signal propagation and supports energy harvesting (EH). This letter proposes a new framework to maximize system throughput in IRS-aided D2D communication, dividing operations into EH and D2D communication stages. An alternating iterative algorithm is employed to jointly optimize the EH duration and the IRS phase shifts for both stages. Sequential quadratic programming (SQP) is utilized to determine the optimal duration of EH, while the phase shift optimization in both stages is achieved through Lagrangian dual transformation, fractional programming, and semidefinite relaxation (SDR). Simulation results validate the proposed approach by demonstrating significant throughput improvements compared to the prior art.