Opportunistic Symbiotic Backscatter Communication Systems

—This paper proposes an opportunistic commensal mechanism (OppCom) and an opportunistic parasitic mechanism (OppPar) for a pair of backscatter devices (BDs) to strengthen the concurrent transmission of the primary and the backscatter systems. It is shown that the asymptotic outage probability of the OppCom and OppPar mechanisms is not affected by the channel statistics between the two BDs. Also, for the OppPar mechanism, the backscatter efﬁciency ratio between the two BDs, instead of their individual values, dominates the system outage performance and a larger difference of the backscatter efﬁciencies leads to a better transmission robustness.