Joint power control and transceiver beamforming with individual secrecy rate constraints for multiuser MIMO

In this paper, physical layer security techniques are studied for the downlink of multiuser multi-input multi-output (MIMO) networks. We aim at minimizing the total transmit power such that individual secrecy rate is satisfied for each user. An iterative joint power control and transceiver beamforming algorithm is developed to achieve this goal. The proposed algorithm is realized by solving the two subproblems. We first study the power control problem with the fixed receiver beamforming. In the following, we obtain the optimal receiver beamforming by minimizing the noise-plus-interference power at the receiver under the condition of unity gain for the signal. The performance is evaluated by considering the impact of individual secrecy rate requirement and number of the transmit antenna. Furthermore, we evaluate the impact of the eavesdropper´s channel state information (CSI). The numerical results demonstrate the effectiveness of the joint transceiver beamforming scheme.