Due to the channel estimation error, most of the physical layer secret key generation schemes need information reconciliation to correct error key bits, resulting in reduced efficiency. To solve the problem, this work proposes a novel secure communication scheme based on a equivalent interference channel. Different keys generated from imperfect channel state information are directly applied to signal scrambling and descrambling, which is equivalent to the process of a signal passing through an interference channel. Legitimate communication parties can reduce interference with the help of similar keys and channel coding without sending additional signals, while the eavesdropper channel is deteriorated due to the spatial decorrelation. For this kind of schemes, we first establish a discrete memoryless broadcast channel model to derive the expressions of bit error rate (BER), channel capacity, and security capacity for performance analysis. Simulation results verify the derivations that the proposed scheme achieves secure communication with a correlated eavesdropping channel and has a higher upper bound of transmission rate. Furthermore, we design a new metric to evaluate the efficiency and the result shows that the proposed scheme has superior performance on error reconciliation efficiency, despite its slight increase in BER.

中文翻译：

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基于物理层秘密密钥辅助的等效干扰信道的安全通信方案

由于信道估计错误，大多数物理层秘密密钥生成方案都需要信息协调以纠正错误密钥位，从而导致效率降低。为了解决该问题，这项工作提出了一种基于等效干扰信道的新颖的安全通信方案。从不完善的信道状态信息生成的不同密钥被直接应用于信号加扰和解扰，这等效于信号通过干扰信道的过程。合法的通信方可以借助相似的键和信道编码来减少干扰，而无需发送其他信号，而窃听者信道则由于空间去相关而恶化。对于这种方案，我们首先建立一个离散的无记忆广播信道模型，以导出误码率（BER），信道容量和安全容量的表达式，以进行性能分析。仿真结果验证了所提方案实现了与相关窃听信道的安全通信，并具有较高的传输速率上限。此外，我们设计了一个新的指标来评估效率，结果表明，尽管BER略有增加，但该方案在纠错效率上仍具有出色的性能。