基于天线分组的携能中继的保密传输方案

由一个单天线的源节点、目的节点和一个多天线的中继节点组成的存在窃听节点的两跳无线网络,研究其在中继节点能量收集约束下的物理层保密传输方案。窃听节点的位置和信道状态不可知,采用由目的节点在第1跳时发送人工噪声进行协作干扰的方式保护两跳传输中保密信息。中继节点采用携能通信工作模式,从接收的信号和人工噪声中提取能量用于信号的转发。第1跳时,中继节点的天线分为两组,分别用于保密信号的接收合并和能量的收集。在第2跳时,中继节点利用所有天线采用波束赋形技术转发信号。由于不能获得窃听信道状态信息,因此以最大化目的节点的速率为目的,对中继节点的转发波束赋形矢量进行优化,并给出一种次优的低复杂度的天线分组策略。仿真结果表明,提出的方案能获得可观的保密速率,提出的天线分组策略的性能明显优于功率分裂策略。

Secure transmission scheme based on SWIPT relay with antenna grouping

A physical layer security transmission scheme is studied in a two hop relay system, which is composed of a source node, a relay node, a destination node and some eavesdroppers. The relay node is equipped with multiple antennas and the others just one. The eavesdroppers’ positions and their channel state information are unknown, so the destination node sends artificial noise to protect the information transmitted in the first and second hop. The relay node works in a simultaneous wireless information and power transfer (SWIPT) mode, and harvests energy from the received signal and artificial noise in the first hop. The harvested energy is used to forward the signals in the second hop. In the first hop, the antennas of relay are divided into two groups, one receiving and combining signals, and the other converting the received signal into energy. In the second hop, the relay node uses all antennas to forward 〖JP2〗signals. Because the eavesdroppers’ channel state information cannot be obtained,the strategy of antenna grouping and signal beamforming vector are optimized through the maximization of the rate of the destination node. A low complexity antenna grouping strategy is given. The simulation results show that an appreciable secrecy rate can be achieved, and it is higher than that when the power splitting strategy is used.