基于极化状态调制的无线通信物理层安全传输技术

Physical Layer Security Transmission Technology Based on Polarization-Shift Keying in Wireless Communications

针对无线通信系统中物理层信息安全风险问题,提出了一种基于极化状态调制的物理层安全传输技术。在无线通信中,引入极化状态调制,在经典的空域、时频域的基础上,增加了对信号极化域的描述。一方面,设计高维星座映射方案,利用信号的幅度、相位和极化状态共同承载信息,将传统调制技术和极化状态调制有效地结合在一起;另一方面,在高维星座映射方案的基础上,进一步设计基于去极化效应的信道预编码机制,通过增大Bob和Eve在极化域的信道差异实现物理层保密传输。安全性分析和仿真实验结果表明,利用该机制能够提升系统的保密容量,在接收信噪比为22dB时,窃听者接收到的星座图仍然是十分紊乱的,无法恢复出有效信息。

Aiming at the physical layer information security risk in the wireless communication system, a physical layer security transmission technology based on polarization shift keying（POLSK） is proposed in this paper. In wireless communications, POLSK is introduced, and the description of the signal in polarization domain is added on the basis of the classical airspace, time and frequency domains. On the one hand, the high-dimensional constellation mapping scheme is designed. Utilize the amplitude, phase, and polarization states of the signal to carry useful information, so that the traditional modulation technology and POLSK can be effectively combined together. On the other hand, based on the high-dimensional constellation mapping scheme, the channel precoding mechanism based on the depolarization effect is further designed to realize the physical layer confidential transmission by increasing the channel difference between Bob and Eve in the polarized domain. Security analysis and simulation and experiment results show that, the mechanism can improve the system＇s secrecy capacity. When the received signal to noise ratio（SNR） is 22 dB, the received constellation is still very chaotic and cannot recover the effective information.