Robust MIMO beamforming and power allocation for artificial noise generated by both transmitter and receiver

This paper is concerned with the secure MIMO transmission in a classic three-node network, in which both the transmitter (Alice) and the receiver (Bob) simultaneously send artificial noise (AN) to impact the channel of the eavesdropper (Eve). Only statistical information about the eavesdropper channel is available. Compared to previous works, this paper studies the scenario in which the main channel are also time-varying and goes through Rayleigh fading. Expected secrecy rate is adopted to evaluate the performance of this model. Robust beamforming and power allocation are proposed to maximize the lower bound of the expected secrecy rate. Numerical results show that with the increase of Bob´s AN power, the best practice is to allocate more dimensions for emitting AN and at the same time distribute a greater proportion of Alice´s power to information symbols.