On the Secrecy Performance of UAV-assisted Wireless Communication System With Hardware Impairments and Protected Zone

This paper analyzes the secrecy performance of UAV assisted wireless communication system considering the imperfect hardware. The UAV acts as an aerial base station and transmits the signal to the ground user in the presence of multiple ground eavesdroppers obeying homogeneous Poisson Point Process (HPPP), where the protected zone strategy is adopted to ensure the security. Based on the statistical characteristics of the channels between the UAV and ground nodes, the cumulative distribution function (CDF) and the probability density function (PDF) of the signal-to-noise-plus-distortion ratio (SNDR) at ground users are deduced. We obtain the analytical closed-form expressions for the average secrecy rate (ASR) and the secrecy outage probability (SOP). Moreover, the asymptotic analysis of ASR are also conducted to get further insights in high signal-to-noise-ratios (SNRs) regime. Finally, we validate the accuracy of the expressions by simulation results and conclude the influence of various system parameters.