This works investigates the covert performance for the satellite aerial ground integrated networks with imperfect limitations, i.e., channel estimation errors, non-ideal hardware and co-channel interference. To enhance the covert transmission, an unmanned aerial vehicle is applied to forward the signal from the satellite source to the destination. Particularly, the detection error probability, outage probability and the covert transmission rate are further studied in the presence of closed-form expressions and asymptotic expressions. Finally, some representative Monte Carlo simulations are proposed to verify our theoretical analysis. Derived from the results, the non-ideal hardware, the channel estimation errors and the co-channel interference have great impacts on the covert performance. Particularly, when the system is under non-ideal hardware, a suitable power allocation scheme is needed for the interference to gain the lowest detection error probability. Moreover, the outage probability has a lower bound in the case of non-ideal hardware. What’s more, the covert transmission rate also has an upper bound when the system is under non-ideal hardware. In addition, to have a better covert performance, the channel state information should be accurate enough by allocating much power for the channel estimations. The finding results are essential for the practical system for they can promote the engineering design.

Covert communication has become a hot topic in the wireless transmission field due to the ability to secure transmitted data by hiding the wireless transmissions. Given the extensive use of drone communications and its urgent demand for security, we investigate covert communications in aerial terrestrial integrated networks (ATINs), where an unmanned aerial vehicle (UAV) tries to send private messages to a remote user via multiple terrestrial relays under the supervisions of the warden. On this foundation, one covert scheme for joint power control and relay selection has been proposed. Subsequently, we derive the detection capabilities at warden, and the effective covert rate (ECR) of link from UAV to user. Furthermore, a power optimization problem is designed to maximize ECR with covertness constraint. Finally, numerical results are presented to verify the achievable covert performance of system and prove the effectiveness of the proposed scheme.

This paper researches the system evaluations of the reconfigurable intelligent surface (RIS)-assisted satellite aerial terrestrial integrated systems. To ensure the stability of the regarded network, a link selection scheme is presented to get the balance between the system performance and the system efficiency. Besides, in order to build a practical environment of the transmission networks, the imperfect hardware, channel estimation errors and co-channel interference are both considered in the networks. Relied on the above considerations, the detailed analysis for the outage behaviors is shown along with the asymptotic outage probability in high signal-to-noise ratio scenarios. Moreover, the diversity order and coding gain are also provided to give fast methods to confirm the system evaluation. Finally, some re-presentative simulations are provided to confirm the efficiency and advantage of analytical results and the proposed link selection scheme.

This paper researches the secrecy outage probabili-ty for the rate splitting multiple access-based integrated satellite-aerial-terrestrial networks. Specially, owing to some practical reasons, imperfect hardware is further analyzed for all the network nodes. Moreover, a UAV is utilized to help the signal transmitting from the satellite to the ground destination in the presence of an eve. Besides, by considering these limitations, the detailed analysis for the secrecy outage probability are gotten, which offer a good way to calculate the impacts of channel parameters and system factors on the secrecy networks. Finally, several representative Monte Carlo simulations are presented to confirm the rightness of the analytical results.

We consider a secrecy dual-hop amplify-and-forward (AF) untrusted relay network, where the relay is willing to forward the signal to the destination while acting as a potential eavesdropper. Assuming that all these nodes are equipped with multiple antennas, we propose a joint destination aided cooperative jamming and precoding at both the source and the relay scheme, with the objective to maximize the worst case secrecy rate. The formulated problem is highly non-convex due to the maximization of the difference of several logarithmic determinant (log-det) functions in the CSI uncertainty region. To handle this challenge, we propose to linearize these log-det terms. After linearization, we tackle the CSI uncertainty based on epigraph reformulation and the sign-definiteness lemma. Finally, an alternating optimization (AO) algorithm is proposed to solve the reformulated problem. Numerical results are provided to demonstrate the performance of the proposed scheme.