Abstract: A physical layer security scheme for CRNOMA systems based on DC(difference of convex) function planning is proposed to address the communication security issues caused by the openness of CRNOMA systems. In the NOMA(nonorthogonal multiple access) communication scenario, construct a multiuser eavesdropping channel model derive the security and rate expressions for the CRNOMA system; And design a DCbased carrier power allocation algorithm to solve the optimal solution for subchannel power allocation and improve the security of system subcarriers. The simulation results show that without increasing the power of the base station, its SSR is improved by 35% and 10%, respectively, compared to OFDMA and NOMA; Under the same SSR, the maximum number of users can increase by 200%. Verified that the scheme can effectively enhance the physical layer security of the system.

Key words: cognitive radio networks, physical layer security, nonorthogonal multiple access, information security, resource allocation

摘要： 针对认知无线电非正交多址接入系统开放性带来的通信安全问题，提出一种基于DC(difference of convex)规划的CRNOMA系统物理层安全方案.在非正交多址(nonorthogonal multiple access, NOMA)通信场景下，构建多用户窃听信道模型，推导出CRNOMA系统的安全和速率表达式；并设计基于DC的载波功率分配算法，求解子信道功率分配的最优解，提高系统子载波的安全性.仿真结果表明，在不增加基站功率情况下，其安全和速率较OFDMA和NOMA分别提升了35%和10%；在相同安全和速率下，用户数量最大可增加200%.验证了该方案能够有效提升系统物理层安全.

关键词: 认知无线电网络, 物理层安全, 非正交多址, 信息安全, 资源分配