Performance analysis of ambient backscattering for green Internet of Things

In this paper, we assess the information-theoretic performance of a point-to-point link that exploits ambient backscattering to support green Internet-of-Thing (IoT) communications. In this framework, an IoT passive device transmits its information by reusing ambient radio-frequency signals emitted by an existing or legacy multicarrier communication system. After introducing the signal model of the relevant communication links, the information-theoretic capacity of both the legacy and backscatter systems is derived. It is found that, under reasonable operative conditions, the legacy system can turn the RF interference arising from backscattering into a form of multipath diversity, which can be exploited to increase its own performance. Moreover, it is shown that, even when it employs simple singlecarrier modulation techniques, the backscatter system attains significant data rates over relatively short distances.