UAV Relay Communications

This section investigates the secrecy performance of a UAV-aided NOMA network in the context of underlay CR. Specifically, a multi-antenna secondary source (S) transmits a mixed signal incorporated with NOMA to two multi-antenna secondary destinations ( \(D_{i}\) ) via a UAV-enabled DF relay in the presence of an eavesdropper (E). In addition, both a transmit antenna selection scheme at S and a maximal ratio combining protocol at \({D_{i}}\) and E are considered. Considering all the links undergo Nakagami-m fading with path loss, we analyze the secrecy performance in terms of SOP for both users. Moreover, we also use Monte Carlo simulations to verify those expressions.