基于干扰对齐的中继MIMO窃听信道安全传输机制

Secure transmission protocol for relay MIMO wiretap channel based on interference alignment

考虑MIMO无线中继网络的安全传输问题,网络中每个节点配备多天线,可获得全部信道状态信息。将干扰对齐与协作干扰相结合,通过预编码使干扰机发送的干扰信号与发送端发送的人工噪声在合法接收端对齐,并与保密信号子空间相互独立,合法接收端可将干扰与人工噪声消除。在窃听端干扰、人工噪声和保密信号处于同一子空间,窃听端无法消除干扰和人工噪声,窃听性能受到较大的抑制。给出了发送端、中继端和干扰机的信号发送和预编码方案,以及合法接收端的干扰消除方案,并从保密速率和保密中断概率两方面对系统的安全性能进行分析和仿真。仿真结果表明,相比于其他系统,保密速率提升,而中断概率下降。

This paper considers the secure transmission for MIMO wireless relay network.Each node is equipped with multiple antennas,and can acquire the global channel state information.The scheme combines the interference alignment and collaboration interference.Using precoding scheme the interference signal sent by jammer is aligned with the artificial noise sent by transmitter at the receiver,and it is independent of confidential signal subspace;then the receiver can eliminate the interference signal and artificial noise.The eavesdropper can also receive the transmitted signal,but it can not eliminate the interference signal and artificial noise as they are in the same subspace with the confidential signal.So its eavesdropping capacity is greatly suppressed.The signal transmission and precoding schemes for the transmitter,relay and jammer are designed,and the interference cancellation scheme for receiver is given.The secrecy performance is analyzed from secrecy rate and secrecy outage probability.Simulation results show that the proposed scheme can improve the secrecy rate and decrease the outrage probability compared with other systems.