A Cross-Layer Analysis for Full-Duplex Ambient Backscatter Communication System

Ambient backscatter communication (AmBC) has great potential to provide Internet of Things (IoT) services with low energy and spectrum cost. In this letter, we study an AmBC system where multiple full-duplex mobile users (MUs) attempt to send packets to the access point (AP) according to the CSMA/CA protocol while receiving the information from their respective associated backscatter devices (BDs). We notice that the transmission of the BD not only decreases the PHY-layer SINR of the CSMA/CA system, but also increases its failure probability of the packet transmission in the MAC-layer. In return, the BD transmission probability is affected by the MAC-layer activity of the CSMA/CA system. To this end, we analyze the cross-layer performance of the AmBC system and quantify the cross-layer outage capacities of the BD and the CSMA/CA systems. Simulation results are provided to verify our theoretical analysis, and demonstrate the interaction between the BD and the ambient CSMA/CA systems.