Covert Communications Versus Physical Layer Security

This letter studies and compares the physical-layer security approach and the covert communication approach for a wiretap channel with a transmitter, an intended receiver and an eavesdropper. In order to make the comparison, we investigate the power allocation problems for maximizing the secrecy/covert rate subject to the transmit power constraint. Simulation results illustrate that if the eavesdropper is not noisy or it is near to the transmitter, covert communication is more preferable.