多发单收窃听信道中人工噪声辅助的鲁棒波束成形设计

A Robust Design of Transmit Beam Forming with Artificial Noises in MISO Wiretap Channels

针对无线通信物理层安全中合法用户接收的信息易受到非法窃听者窃听的问题,提出了一种人工噪声辅助的鲁棒波束成形(AN-RBF)设计方案。首先,利用信道估计分别获取发射端到合法用户的瞬时非理想信道状态信息(CSI)和发射端到窃听者的统计CSI;然后,在发射端向合法用户发送的信号中添加人工噪声,通过对有用信号和人工噪声进行联合优化,在满足发射功率控制和中断概率限制的约束条件下实现安全传输速率的最大化。AN-RBF方案发射端仅需获取窃听者的统计CSI,且发射端获取的合法用户的瞬时CSI是非理想的,系统开销少,另外,人工噪声的添加可以降低窃听者接收端信干噪比,提高多发单收(MISO)窃听信道中的安全传输速率。仿真结果表明,在20dB功率且仿真环境相同的情况下,所提AN-RBF方案的安全速率比各态同向人工噪声辅助方案提高了约2bit·(s·Hz)-1。

A robust beam forming（AN-RBF）scheme with artificial noises is proposed to improve the physical layer for the wireless communication.Firstly,the channel estimation is used to get the imperfect channel state information（CSI）of a legitimate receiver and the statistical CSI of eavesdroppers.Then,the AN-RBF scheme adds artificial noises into transmission signals to maximize the secrecy rate under constraints of the transmit power and the secrecy rate outage probability.The AN-RBF scheme only needs to get the imperfect CSI of the link to the legitimate receiver and the statistical CSI of the link to eavesdroppers,therefore,reduces the system overhead.Adding artificial noise effectively reduces the signal-to-interference-and-noise ratio（SINR）received at eavesdroppers.Thus,the AN-RBF scheme improves the physical layer security performance of multiple-input single-output（MISO）wiretap channels.Simulation results and a comparison with the isotropic AN scheme in the same simulation environment show that the AN-RBF scheme improves the secrecy rate approximately by 2 bit·（s·Hz）-1.