AAV-Assisted AmBC Network: Performance Analysis in Nakagami-$m$ Fading Channel

The unmanned aerial vehicle (UAV)-assisted ambient backscatter communication (AmBC) network has a wide range of applications and can efficiently establish wireless links for Internet of Things (IoT) nodes. In this paper, we analyze the performance of the UAV-assisted AmBC network over Nakagami-<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$m$</tex-math></inline-formula> fading channels. In this network, there are two different transmission links: a legacy link and multiple AmBC links, where one of the AmBC links is randomly selected for backscattering communication. For the randomly selected AmBC link, two main factors caused information outages are analyzed: the energy outage and the interference outage. Based on the probability density function of the Nakagami-m fading channel gain, the closed-form expressions of the outage probabilities are derived by using the Gauss-Laguerre approximation. Furthermore, we calculate the asymptotic outage probability, ergodic capacity, and diversity gain through theoretical derivation. For the air-to-ground legacy link, the reasons of the primary user's outage are analyzed as the transmission outage caused by air-ground channel attenuation and the interference outage caused by the high transmission power of the AmBC link. Building upon different cases, the closed-form expressions of the outage probabilities are also calculated. In addition, the related performance of the legacy link is also further studied. The simulation results show the performance of the two mentioned links under different parameters and verify the effectiveness of the network.