In this paper, we propose a securely precoded OFDM (SP-OFDM) system for efficient and reliable transmission under disguised jamming, where the jammer intentionally misleads the receiver by mimicking the characteristics of the authorized signal and causes complete communication failure. More specifically, we bring off a dynamic constellation by introducing secure randomness shared between the legitimate transmitter and receiver, and hence, break the symmetricity between the authorized signal and the disguised jamming. We analyze the channel capacities of both the traditional OFDM and SP-OFDM under hostile jamming using the arbitrarily varying channel (AVC) model. It is shown that the deterministic coding capacity of the traditional OFDM is zero under the worst disguised jamming. On the other hand, due to the secure randomness shared between the authorized transmitter and receiver, SP-OFDM can achieve a positive capacity under disguised jamming since the AVC channel corresponding to SP-OFDM is not symmetrizable. A remarkable feature of the proposed SP-OFDM scheme is that while achieving strong jamming resistance, it has roughly the same high spectral efficiency as the traditional OFDM system. The robustness of the proposed SP-OFDM scheme under disguised jamming is demonstrated through both theoretic and numerical analyses.

中文翻译：

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伪装干扰下的安全 OFDM 系统设计和容量分析


在本文中，我们提出了一种安全预编码 OFDM (SP-OFDM) 系统，可在伪装干扰下实现高效可靠的传输，其中干扰器通过模仿授权信号的特征故意误导接收器并导致完全通信失败。更具体地说，我们通过引入合法发射器和接收器之间共享的安全随机性来实现动态星座，从而打破授权信号和伪装干扰之间的对称性。我们使用任意变化信道 (AVC) 模型分析了传统 OFDM 和 SP-OFDM 在敌对干扰下的信道容量。结果表明，在最恶劣的伪装干扰下，传统的正交频分复用技术的确定性编码能力为零。另一方面，由于授权发射机和接收机之间共享的安全随机性，SP-OFDM可以在变相干扰下实现正容量，因为与SP-OFDM相对应的AVC信道是不可对称的。所提出的SP-OFDM方案的一个显着特点是，在实现强抗干扰能力的同时，它具有与传统OFDM系统大致相同的高频谱效率。通过理论和数值分析证明了所提出的 SP-OFDM 方案在伪装干扰下的鲁棒性。