Physical layer security, as an important practical concept, in unmanned aerial vehicle (UAV) assisted channels has been studied in the literature, where, correlation impact of wireless channel coefficients has not been considered. In this paper, having briefly reviewed (the discrete memoryless channel, physical secure rate and copula function theory), a continuous alphabet wiretap channel with UAV transmitter is considered. For this channel, we obtain closed form expressions for secrecy capacities in two cases: (i) Gaussian channel with constant channel coefficients; (ii) Gaussian wireless channel with correlated coefficients by using FGM copula function to describe the correlations. Through obtained secrecy rates, we analyze the impacts of (a) UAV situation for transmitter (b) correlation between channel coefficients on the achievable rates. Then, analytical results are numerically assessed across various correlation structures. The findings demonstrate that correlated fading adversely impacts security performance.

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