Delay-QoS-driven robust power allocation over full-duplex relay multicarrier secure system

In this paper, we investigate the power allocation policy under channel uncertainties over the full-duplex (FD) relay multicarrier secure communication system. Considering the requirement of the statistical delay quality-of-service (QoS), an optimization problem of maximizing the secure effective capacity under the constrains of powers of both the whole system and the residual loop-interference (LI) of FD relay is formulated to study the robust power allocation via the worst case method. Furthermore, after simplifying the original optimization problem by Taylor approximation, we obtain the optimal solution by using Lagrange dual method and Karush-Kuhn-Tucker (KKT) conditions. Simulation results illustrate the advantages of the proposed robust power allocation strategy and the trade-off between the secure effective capacity and robustness can be achieved.