基于空域加扰的保密无线通信统一数学模型及其窃密方法
摘要
The spatial scrambling based wireless transmission methods, such as artificial noise and antenna array weighted randomly, can secure wireless communication at the physical layer. They have a common phys- ical essence, that is, the private message is transmitted in the desired direction while deliberate interference is transmitted in other orthogonal directions. Unfortunately, the interference is not white in spatial domain due to the limitation of the transmit antenna number. An eavesdropper can eliminate the directional interferences by the aid of multiple antennas. In this paper, a unified mathematical model for the above physical-layer methods is established, based on which, a MUSIC-like wiretap algorithm is proposed by exploiting the finite alphabet property of communication symbols. Simulation results show that if the eavesdropper has more antennas than that of the transmitter, the proposed algorithm can intercept information effectively.