Ambient Backscatter-assisted Relaying in Symbiotic Radio Networks with Energy Harvesting: Performance Analysis

The proliferation of Internet of Things (IoT) devices in the transition towards 6G networks demands ultra-energy-efficient communication solutions capable of supporting massive connectivity. Ambient Backscatter Communication (AmBC) integrated with Energy Harvesting (EH) has emerged as a promising paradigm to address this challenge by enabling battery-free operation. This paper investigates the performance of an Ambient Backscatter-Assisted Relaying system employing a linear Energy Harvesting protocol. Specifically, we consider a system model where an energy-constrained backscatter device harvests energy from a source signal using a power splitting (PS) scheme and subsequently reflects information to a destination. We derive closed-form expressions for the system\'s Outage Probability (OP) over Rayleigh fading channels. The validity of the proposed mathematical framework is rigorously confirmed through extensive Monte-Carlo simulations. Furthermore, we extensively evaluate the impact of various critical parameters, including the power splitting factor, transmit Signal-to-Noise Ratio (SNR), target data rates, and channel qualities, on the system\'s outage performance. The analysis provides quantitative assessments of the trade-offs between energy harvesting efficiency and data transmission reliability, offering valuable insights for optimizing resource allocation in future low-power IoT networks.