Robust security-aware beamforming design for cognitive radio networks

We study the robust security-aware beamforming optimization for cognitive interference channel with confidential messages under the imperfect channel state information (CSI) at each cognitive transmitter. The considered problem is formulated as minimizing the total secondary transmitter power under the subject of the each secondary transmitter constraint while guaranteeing the security communication with each SU quality of service (QoS) as well as interference temperature constraints, so as to satisfy the requirement of future green communication. In order to solve this intractable non-convex problem, we convert the original problem to a standard semi-definite programming (SDP) by dropping the rank-1 constraints with the aid of a conservative approximation approach. Numerical results finally verify the effectiveness of our proposed algorithm and illustrate its advantage over the conventional approaches.