中文摘要：

针对现有的物理层安全技术缺乏以瑞利衰落信道为研究背景的安全性能分析,建立瑞利衰落信道下的窃听模型,首先分别用平均解码速率和平均发送速率来衡量传输系统的有效性和安全性,并推导其解析表达式。然后,将传输系统有效性和安全性的折中问题建模为多目标优化问题,通过线性加权和法进一步将其转化为单目标优化问题,并给出基于梯度下降法的最优发送速率求解算法。最后,通过数值仿真分析信号发送速率、窃听者位置、循环迭代次数等因素对系统安全性能的影响。

英文摘要：

According to the existing physical layer security technology lack of security performance analysis over Rayleigh fading channel, this paper establishes the wiretap model over the Rayleigh fading channel. Firstly, the average decoding rate and the average eavesdropping rate are used to measure the effectiveness and safety of the transmission system and their analytical expressions are derived. Then, the compromise of the safety and effectiveness is modeled as a multi-objective optimization problem, which is further transformed into a single objective optimization problem by using the linear weighted method. Besides, an optimal transmis-sion rate algorithm is given based on gradient descent method. Finally, the simulation results show the effects of the signal transmis-sion rate, the eavesdropping position, the number of loop iterations and other factors on the security performance.