https://jjcit.org/paper/285 10.5455/jjcit.71-1765426560 Lam-Dong Huynh,Lam-Thanh Tu,Quang-Sang Nguyen,Tan N. Nguyen Ambient backscatter communication,Energy harvesting,Outage probability,Relay-assisted network,Imperfect successive interference cancellation,Imperfect channel state information 600 130 11-Dec.-2025 1-Feb.-2026 22-Feb.-2026 Ultra-energy-efficient communication solutions are required as Internet of Things (IoT) devices proliferate in the shift to 6G networks. In this paper, a novel architecture that uses energy harvesting (EH) protocols to integrate Ambient Backscatter Communication ( ���� ) as a passive relay is investigated. An energy-constrained backscatter device uses a power splitting (PS) mechanism to both reflect its information to the destination and harvest energy for circuit activation. The main contribution of this work is the development of new and accurate closed-form expressions for the system outage probability (OP) over Rayleigh fading channels. Extensive Monte Carlo simulations are conducted to rigorously validate the accuracy of the proposed analytical framework. The analysis reveals important trade-offs between transmission reliability and energy-harvesting efficiency, providing valuable insights for resource optimization in future low-power IoT networks. The results demonstrate that the adverse effects of imperfect successive interference cancellation (SIC) and/or imperfect channel state information (CSI) can be effectively mitigated by increasing the transmit power and/or operating at the optimal value of the reflection coefficient. Moreover, the performance gap between perfect and imperfect SIC and CSI is shown to be relatively small. Finally, we analytically prove that the linear EH model serves as an upper bound for the practical nonlinear EH model.