Secrecy-rate balancing for two-user MISO interference channels

This paper considers a two-user multiple-input single-output (MISO) interference channel with confidential messages (IFC-CM), where the beamforming vectors at the two transmitters are jointly optimized using the closed-form Pareto-optimal parameterization. We show that coordinated beamforming is secrecy-rate optimal which is achieved by agreeing on the parameters between the two transmitters. We first analyze the feasible set of the beamforming parameters that guarantees positiveness of the secrecy rates. We then derive a quadratic relationship that finds the Pareto-optimal parameters to achieve secrecy-rate balancing beamforming.