Outage Probability Analysis of the Symbiotic Backscatter-NOMA Systems

Non-orthogonal multiple access (NOMA), a promising technology in next-generation communication systems, which enjoys high spectral efficiency by using an extra multiplexing dimension in the power domain. Meanwhile, ambient backscatter communication (AmBC) has been intensively studied in Internet of Things (IoT) application scenarios due to its low power consumption. In this paper, a symbiotic system of IoT networks combining NOMA technology with multiple backscatter devices (BDs) is proposed. To analyze the performance of the proposed system, the expression of outage probability is derived over Rayleigh fading channels, and its diversity gain is also analyzed. Finally, these analyses are validated via numerical results and compared with those in conventional backscatter NOMA with single BD systems.