Robust beamforming and artificial noise design in interference networks with wireless information and power transfer

In this paper, the robust beamforming and artificial noise design is investigated in two-user interference networks with wireless information and power transfer. Specifically, we focus on the secure communication of the two pairs in the presence of an energy receiver (ER) which acts as the potential eavesdropper and intends to wiretap the confidential message transmitted to one of the information receivers (IRs). With only imperfect eavesdropper’s channel state information (ECSI) at the transmitters, our goal is to minimize the total transmit power, while guaranteeing the worst-case secrecy rate requirement at the wiretapped IR, the signal-to-interference-plus-noise ratio requirement at the wiretap-free IR and the energy harvesting requirement at the ER. In particular, we first model the imperfect ECSI in the sense of ellipsoidal uncertainties. Then, our design goal can be further reformulated as a two-stage optimization problem. With the help of rank relaxation and one-dimensional line search, the considered two-stage problem can be solved efficiently. Simulation results verify the effectiveness of the proposed design in different scenarios.