In this paper, we research a synthesis scheme for secure wireless communication in the broadcasting multiusers directional\nmodulation system, which consists of multiple legitimate users (LUs) receiving the same confidential messages and multiple\neavesdroppers (Eves) intercepting the confidential messages. We propose a new type of array antennas, termed random frequency\ndiverse arrays (RFDA), to enhance the security of confidential messages due to its angle-range dependent beam patterns. Based on\nRFDA, we put forward a synthesis scheme to achieve multiobjective secure wireless communication. First, with known locations\nof Eves, the beamforming vector is designed to minimize Evesâ?? receiving power of confidential message (Min-ERP) while\nsatisfying the power requirement of LUs. Furthermore, we research a more practical scenario, where locations of Eves are\nunknown. Unlike the scenario of known locations of Eves, the beamforming vector is designed to maximize the sum received\npower of LUs (Max-LRP) while satisfying a minimum received power constraint at each LU. Second, the artificial-noise projection\nmatrix (ANPM) is calculated to reduce artificial-noise (AN) impact on LUs and enhance the interference on Eves. Numerical\nresults verify the superior secure performance of the proposed schemes in the broadcasting multiusers system.
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