星-地混合通信网络前向链路安全传输方案研究

针对星-地混合通信网络前向链路在部分非理想信道状态信息(CSI)及非理想CSI下卫星窃听链路的安全问题，提出一种将地面基站信号作为协同干扰的安全传输方案。优化目标为地面基站节点传输速率最大，确保卫星合法节点接收信号质量，同时利用地面基站发送信号阻塞卫星潜在窃听节点对卫星信号的侦听。通过半定松弛原理将其转化为可解的凸优化问题，分别设计分层迭代、高斯随机化和二分搜索算法对问题进行优化求解。仿真校验结果表明，所提方案能够降低网络对CSI误差的敏感性，提高网络的可靠性和保密性。

Research on Secure Transmission of Forward Link in Hybrid Satellite Terrestrial Communications Networks

For the secrecy problem of eavesdropping link with partly imperfect channel state information (CSI) and imperfect channel state information in the forward link of hybrid satellite-terrestrial communications networks, this paper proposes a secure transmission scheme which considers the signals of the terrestrial base station as a cooperative interference. The optimization target is to maximize the transmission rate of the terrestrial base station node and ensure the QoS of the satellite legitimate terminal, while jamming the satellite potential eavesdropper by using the signals of the terrestrial base station. The secure transmission scheme is transformed into the convex optimization problems by using the semi-definite relaxation principle, respectively solved by the layer-iterative, Gauss randomized, and binary search algorithms. The simulation results show that the proposed schemes can reduce the sensitivity of the networks to the CSI error and improve the networks reliability and security.