研究节点具备能量收集能力的中继窃听信道保密速率的优化问题,提出一种基于人工噪声协同干扰和节点间能量协同的物理层安全传输策略.各节点采用储能-发送模式工作,即先收集能量,再用于数据传输.中继节点采用放大转发方式,目的节点发送人工噪声进行协同干扰.由于中继节点所需功耗较高,目的节点将用于发送干扰之外的剩余能量转移给中继节点.给出以最大化保密速率为目标函数,优化能量吸收时间比例系数和干扰功率分配因子的两步优化算法.仿真结果表明人工噪声和能量协同的引入能有效提高系统的保密传输速率.
The optimization of secrecy rate is studied in the wireless relay-eavesdropper channel in which the nodes harvest energy. An enhanced physical layer security communication scheme is proposed based on artificial noise-aided cooperative jamming and energy cooperation. All nodes followthe save-then-transmit protocol. The nodes harvest energy first,which is then used to transmit the data. The relay is operated as an amplify-and-forward relay,and the destination sends intended jamming noise to protect information. Since the relay requires more energy,surplus energy is transferred from the destination to the relay to increase the available power of the relay. A two-step optimization algorithm to maximize the secrecy rate is derived through the optimization of the energy-saving time ratio and the jamming power allocation scaling factor. The simulation results prove that the proposed energy cooperation scheme can effectively improve secrecy rate.