  An artificial-noise (AN)-aided beamformer specific to correlated main and
wiretap channels is designed in this paper. We consider slow-fading
multiple-input-single-output (MISO) wiretap channels with a passive
single-antenna eavesdropper, in which independent transmitter-side and
correlated receiver-side are assumed. Additionally, the source has accurate
main channel information and statistical wiretap channel information. To reduce
the secrecy loss due to receiver-side correlation, this paper proposes the
scheme of channel-correlation-enabled transmit optimization. Particularly, the
correlation is viewed as a resource to acquire more knowledge about wiretap
channel. Based on this, the statistical distribution of wiretap channel is
described more precisely. Then, the power of AN in the null space of main
channel is placed more reasonably instead of simple uniform distribution and an
elaborate beamformer for the information-bearing signal is designed. Finally,
an efficient algorithm for power allocation between the information-bearing
signal and the AN is developed. Simulation results show that the secrecy rate
under transmit power and secrecy outage constraint is improved.
