Optimal Secure Transmission with Artificial-noise-aided Beamforming in Multi-cell Networks

Safe and reliable wireless transmission services are needed in multi-cell massive MIMO mobile communication networks. Physical layer security technology is effective to solve wireless networks transmission security issues. It uses the channel characteristics of wireless to encrypt information so as to improve confidentiality security of communication. Combined with multi-cell cooperation, this paper proposes optimal secure transmission with artificial-noise-aided beamforming, which applies base station selection, in multi-cell massive MIMO networks. In the proposed secure transmission scheme, the optimal base station among all cells is selected which assists generating artificial noise to deteriorate the channel quality of eavesdroppers. The multi-cell communication models under two different base station selections are considered and the lower bounds of the ergodic secrecy rate of the two selections are derived respectively. The genetic algorithm is utilized to optimize the power allocation by maximizing the lower bound of the ergodic secrecy rate. Simulation results show the effectiveness of the proposed transmission scheme.