Performance Analysis of NOMA-Based Symbiotic Ambient Backscatter Communication.

Non-orthogonal multiple access (NOMA) and ambient backscatter communication (AmBC) are promising technologies to enable spectrum efficiency in wireless communication systems. In this paper, we propose a downlink NOMA multiplexing-based Symbiotic radio (SR) AmBC system over Rayleigh fading channels. The system consists of one source node S, one backscatter device (BD), one nearby cellular user (User 1), and one far-away cellular user (User 2). In light of a viable non-linear energy harvesting (EH) model, we implement the most effective dynamic reflection strategy to enhance the backscattered signal's power, adhering to the BD's energycausality limitations. The analytical expressions for the outage probability of the proposed system are derived. Moreover, we compared the performance of the NOMA-based system against the OMA-based system. Simulation results verified our derived expressions and showed that the consumed power by the BD had a remarkable influence on the system outage performance. [ABSTRACT FROM AUTHOR]