Cooperative Ambient Backscatter System: A Symbiotic Radio Paradigm for Passive IoT

TLDR

Cooperative ambient backscatter is a symbiotic radio paradigm where passive backscatter shares spectrum and RF source with active primary transmission. The study proposes three practical symbiotic transmission schemes—commensal, parasitic, and competitive—tailored to the ambient backscatter system. The authors derive achievable rates for both primary and backscatter links under specific fading states and determine optimal power allocation for each scheme under an average power constraint. Simulations confirm the theoretical analysis.

Abstract

Cooperative ambient backscatter system is a novel symbiotic radio paradigm, in which the passive backscatter transmission shares not only the same spectrum but also the same radio-frequency source with the active primary transmission. By considering the unique features of the ambient backscatter system, three practical symbiotic transmission schemes are proposed, in which the relationships between the primary and backscatter transmissions are commensal, parasitic, and competitive, respectively. The achievable rates for both primary and backscatter transmissions are derived for particular fading state. Then, optimal power allocation is obtained for each transmission scheme under the average power constraint. Simulation results are provided to corroborate theoretical studies.