In this paper, a novel design named security-oriented polar coding (SOPC) is proposed to enhance the physical layer security (PLS), where the active pattern of frozen bits in a transmission is determined by random channel gain of the legitimate link. Since the channel gain value is not exchanged between the legitimate transmitter and the desired receiver, eavesdroppers cannot ascertain the frozen bit pattern engaged in the legitimate polar coding. When the signal-to-noise ratio (SNR) is low, eavesdroppers are unable to appropriately decode the confidential information delivered over the legitimate link. As the SNR increases, eavesdroppers may have chance to sort out the correct frozen bit pattern through a brute-force search. However, this chance is significantly reduced by our SOPC. We design the SOPC for both single-input-single-output single-antenna eavesdropper (SISOSE) and multiple-input-multiple-output multi-antenna eavesdropper (MIMOME) channels. Its PLS functioning is assessed in terms of the error rate difference between the legitimate receiver and the eavesdropper. Illustrative simulation results substantiate that the SOPC design guarantees degraded decoding performance at eavesdroppers, for both SISOSE and MIMOME channels, even in the presence of a powerful eavesdropper possessing infinite computational resources.

中文翻译：

---

基于信道增益映射冻结比特的安全极性编码

在本文中，提出了一种名为面向安全的极性编码（SOPC）的新颖设计来增强物理层安全性（PLS），其中传输中冻结比特的活动模式由合法链路的随机信道增益决定。由于合法发射机和所需接收机之间不交换信道增益值，因此窃听者无法确定参与合法极性编码的冻结比特模式。当信噪比 (SNR) 较低时，窃听者无法正确解码通过合法链路传递的机密信息。随着 SNR 的增加，窃听者可能有机会通过暴力搜索找出正确的冻结位模式。但是，我们的 SOPC 大大降低了这种机会。我们为单输入单输出单天线窃听器 (SISOSE) 和多输入多输出多天线窃听器 (MIMOME) 通道设计了 SOPC。它的 PLS 功能是根据合法接收者和窃听者之间的错误率差异来评估的。说明性仿真结果证实，即使存在拥有无限计算资源的强大窃听者，SOPC 设计也保证了窃听者对 SISOSE 和 MIMOME 通道的解码性能下降。