在无线网络中,当利用经典博弈机制研究物理层安全时,能量受限的发送端为了最大化自身安全速率,趋向于选择非协作策略,造成网络的安全速率降低。针对这一问题,该文提出一种基于演化博弈机制的物理层安全协作方法。首先,根据演化博弈机制定义策略(发送人工噪声或信号)和收益(不同策略组合下的安全速率);然后,发送端根据当前网络状态以及协作收益与平均期望收益的差值,不断进行策略调整以最大化收益;最后,通过求解获得使发送端达到协作稳定策略的条件,使网络从不稳定状态向协作稳定状态演化,从而提高了系统的安全速率。仿真和分析结果表明,在高斯信道条件下,相比经典博弈方法,该方法的发送端策略稳定在协作状态,网络安全速率可提高1 bit/(s?Hz)。
In wireless networks, when using traditional game studying physical layer security, the energy-limited transmission nodes tend to choose a non-cooperative strategy in order to maximize their own secrecy rate, resulting in reduced network secrecy rate. To solve this problem, this paper presents a method for physical layer security cooperation based on evolutionary game. Firstly, this study defines strategies(sending artificial noise or signal) and benefits(secrecy rate under different strategy combination) according to evolutionary game; then, the transmission nodes adjust strategy to maximize benefits based on current network state and difference between cooperation utility and average expected utility; finally, the conditions that the transmitting nodes can achieve stable cooperation, are obtained, and the network evolution from an unstable state to a stable collaboration state improves the secrecy rate of the system. The simulation and analysis results show that under the Gaussian channel conditions, compared to traditional game method, the proposed method’s network secrecy rate can be improved 1 bit/(s ?Hz).