Abstract: For preventing the leakage of confidential messages in multiuser multiple-input single-output (MISO) interference channels, a secure coordinated beamforming (SCB) scheme was proposed for the perfect channel state information (CSI) case and a robust secure coordinated beamforming (RSCB) scheme for the imperfect CSI case. Under the perfect CSI, the beam forming vectors at transmitters were jointly optimized to maximize the minimum secrecy rate. The locally optimal solution to the original non-convex problem was obtained using the semidefinite relaxation (SDR) technique and the successive convex approximation (SCA) algorithm. Moreover, the framework was generalized to the case of imperfect CSI with the deterministic errors in both channel vector and channel covariance matrix. The RSCB scheme was used to maximize the worst-case secrecy rate. Simulation results validate the efficacy and the robustness of the proposed schemes.

Key words: secrecy rate; interference channel; coordinated beamforming; semidefinite programming; successive convex approximation