Robust Power and Position Optimization for the Full-Duplex Receiver in Covert Communication

Covert communication achieved by using the full-duplex (FD) receiver has wide applications. Specifically, the FD receiver can emit artificial noise to prevent the signal of transmitter from detecting by the illegitimate warden. In this paper, we investigate the robust joint power and position optimization (JPPO) for the full-duplex receiver (i.e., Bob) in the presence of the uncertainties of the warden (i.e., Willie). We first analyze the effect of the warden's position uncertainty on the performance of covert communication. Then, by using robust optimization technique, we maximize the effective covert throughput of transceivers by optimizing the power and position of the Bob constraining the sufficient covertness requirement. Theoretical analysis indicate that the effective covert throughput between Alice and Bob is inversely proportional to the distance between them within the deployable zone (DZ) satisfying the covert condition, and the optimal position of Bob is on the boundary of the DZ near Alice. Finally, simulation results verified our conjecture.