Abstract: The physical layer secure transmission in two-way multi-relay system can not obtain the accurate Channel State Information (CSI) of eavesdroppers. In order to solve the problem, a robust joint physical layer secure transmission scheme of multi-relay cooperative beamforming and artificial noise was proposed to maximize the secrecy sum rate in the worst case of channel state under the total power constraint of system. In the proposed scheme, the problem to be solved was a complex non-convex optimization problem. The alternating iteration and Successive Convex Approximation (SCA) methods were used for the alternating optimization iteration of beamforming vector, artificial noise covariance matrix and source node transmit power, and the optimal solution of the above problem was obtained. The simulation results verify the effectiveness of the proposed scheme and show that the proposed scheme has better security performance.

Key words: two-way relay communication system, physical layer secure communication, Secrecy Sum Rate (SSR), artificial noise, beamforming

摘要： 针对双向多中继系统物理层安全传输无法获取窃听者的精确信道状态信息（CSI）的问题，提出鲁棒的多中继协作波束形成和人工噪声联合物理层安全传输方案，以最大化系统总功率约束下信道状态"最差情况"时的安全总速率。在该方案中，待求解的问题是一个复杂的非凸优化问题。采用交替迭代和连续凸近似（SCA）方法，对波束形成向量、人工噪声协方差矩阵和源节点发射功率进行交替优化迭代，得到了问题的优化解。仿真实验验证了所提方案的有效性，并表明该方案具有更优的安全性能。

关键词: 双向中继通信系统, 物理层安全通信, 安全总速率, 人工噪声, 波束形成