Covert Communication for Satellite Aerial Ground Integrated Networks Under Imperfect Limitations

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.