该文从用户服务质量(QoS)的角度研究了多输入单输出(MISO)认知无线电网络的物理层安全问题。通过在次用户的发送信号中加入适当功率的人为噪声,能够有效地提高网络的物理层安全性能。经过适当的变换,将次用户的安全优化问题转化为一个半定规划,从而可以有效地求得次用户的最优发射方案。另外,针对信道状态信息不确定性的问题,在假设已知信道状态信息误差范围的前提下,采用最差性能最优的方法对系统进行鲁棒性设计,以保证即使在信道状态信息误差最大的情况下,依然可以满足系统的约束条件。最后,通过仿真验证了算法的有效性。
This paper studies on the issue of physical layer security of MISO Cognitive Radio Networks(CRN) from the Quality of Service(QoS) perspective.By adding a suitable amount of artificial noise into the transmitting signal of the Secondary User Transmitter(SU-Tx),the security performance could be enhanced apparently. Through some appropriate transformations,the optimization problem is converted into a semi-definite programming,which can be easily solved.Furthermore,a robust optimal transmitter is designed by using the worst-case optimization approach on the premise of knowing the region of uncertainties of Channel State Information(CSI).Therefore,all the constraints can still be satisfied even with the maximal CSI errors.Simulation results verify the effectiveness of the proposed approach.