非理想信道下基于人工噪声的密集异构蜂窝网安全传输方案

Artificial Noise Aided Secure Transmission in Dense Heterogeneous Cellular Networks with Imperfect Channel State Information

针对密集异构蜂窝网在非理想信道状态信息条件下的安全传输问题,该文分析了人工噪声对通信的可靠性和安全性的影响,在此基础上提出功率分配优化模型,在不同信道估计精度条件下给出了最优的功率分配因子。首先,考虑信道估计误差对合法信号传输以及人工噪声泄露的影响,推导了典型通信链路的连通中断概率和安全中断概率。然后,在安全性和可靠性约束条件下建立功率分配优化模型以最大化系统安全吞吐量,并通过K维联合搜索算法得到每层网络的最优功率分配因子。最后,仿真结果表明系统设置最优功率分配因子时,人工噪声方案可提升约15%的安全吞吐量。

To ensure secure transmission in dense heterogeneous cellular networks with imperfect Channel State Information （CSI）, the influence of Artificial Noise （AN） on secure and reliable communication is analyzed, and a power split factor optimization model is presented to obtain the optimal value under different channel estimation accuracy. First, the connection outage probability and secrecy outage probability are deduced by considering the influence of channel estimation error on signal transmission and AN leakage. Then, a power split factor optimization model is presented, which maximizes the secrecy throughput subject to the security and reliability requirements. A K-dimensional search method is employed to solve the optimal power split factor of each tier. Finally, the numerical results verify that the AN transmission scheme with optimal power split factor can increase secrecy throughput by about 15%.