AN-Aided Secure Beamforming Design for Correlated MISO Wiretap Channels

An artificial-noise (AN)-aided beamformer for reducing secrecy loss due to the correlation between the main and wiretap channels is designed in this letter. We consider slow-fading multiple-input-single-output wiretap channels with a passive single-antenna eavesdropper, where the source has accurate main channel information and statistical wiretap channel information. By exploiting the channel correlation, the power of the AN in the null space of the main channel can be placed more reasonably instead of using a simple uniform distribution. Then, an efficient algorithm for power allocation between the information-bearing signal and the AN is developed. The simulation results show that the secrecy rate under the transmit power and secrecy outage constraint is improved.