人工噪声辅助的保密通信及其窃听算法

Artificial noise aided secure communication and its eavesdropping method

无线网络的开放性使得其信息传输的安全性面临更大挑战。一种通过在窃听信道发射人工噪声来干扰窃听者的方法被广泛研究,并用于保障物理层安全通信。分析了人工噪声方法的不足,推导了其安全通信的必要条件,提出一种有效的窃密算法来对抗该安全机制。该算法中,当窃听者拥有比发射机更多数量的天线时,可以抑制接收到的人工噪声,且能采用复值独立分量分析(independent component analysis,ICA)将私密信息截获。数值仿真验证了该窃密算法能够对抗人工噪声、获得良好的窃听效果。

The broadcast nature of wireless network leads to significant challenges to its information security. Recently, artificial noise （AN） is proposed to be injected into the wiretap channel to interfere the eavesdropper for secret communication at the physical-layer. In this paper, we investigate the necessary condition for this AN-aided scheme to ensure communication security, and further propose an effective wiretap algorithm to counteract such a security scheme. When the eavesdropper equips more antennas than the transmitter, it is able to cancel artificial interference and extract the secret information by complex-valued independent component analysis（ICA）. Numerical simulation results verify that our proposed algorithm can defeat the AN-aided security scheme and implement eavesdropping effectively.