IRS辅助NOMA网络下隐蔽通信性能研究

Performance analysis of covert communication in IRS-assisted NOMA networks

隐蔽通信是保证无线通信安全的关键技术之一.为增强通信的安全性,提出了智能反射面辅助的非正交多址接入系统的隐蔽通信传输方案.考虑到信道估计误差和非完美串行干扰消除两种非理想因素,首先推导出监测者的检错误概率和最佳阈值精确表达式,然后给出了平均最小检测错误概率和用户的中断概率.最后,平衡网络的可靠性和隐蔽性,以最大化系统的有效隐蔽速率.仿真结果表明,所提方案可以实现隐蔽通信,并且系统有效隐蔽速率存在上限.此外,非理想信道状态信息和非完美串行干扰消除会恶化系统性能.

Covert communication is one of the key technologies to ensure the security of wireless communications.To enhance the communication security,covert communication of intelligent reflecting surface(IRS)-assisted nonorthogonal multiple access(NOMA)systems is proposed.Considering the channel estimation errors and imperfect successive interference cancellation(SIC),the exact expressions of the detection error probability(DEP)and the optimal detection threshold of the Willie are derived,and then the average minimum DEP(AMDEP)and outage probabilities(OP)for the two NOMA users are given.Finally,the reliability and covertness of the network are balanced to maximize the effective covert rate(ECR)of the system.Simulation results show that the proposed scheme can achieve covert communication,and there exists an upper bound for the ECR of the system.Furthermore,the non-ideal channel state information(CSI)and imperfect SIC have deleterious influence on the system performance.