In this letter, we present a novel and important performance metric for analyzing and evaluating the physical layer security of wireless communication systems in the presence of eavesdropping users. Specifically, we introduce the concept of amount of secrecy loss and derive the expressions that can quantify the severity of loss in systems with eavesdropping users. In addition, a new method for calculating the average secrecy rate is proposed. We further evaluate the performance of cooperative communication systems with the proposed performance metric to observe the behavior of different relaying schemes. Finally, simulation results are provided to verify the accuracy of the presented analytical expressions.

中文翻译：

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保密损失量：物理层安全分析的新指标

在这封信中，我们提出了一种新颖且重要的性能指标，用于在存在窃听用户的情况下分析和评估无线通信系统的物理层安全性。具体来说，我们引入了保密损失量的概念，并推导出可以量化具有窃听用户的系统中损失严重程度的表达式。此外，还提出了一种计算平均保密率的新方法。我们使用所提出的性能指标进一步评估协作通信系统的性能，以观察不同中继方案的行为。最后，仿真结果验证了所提出的解析表达式的准确性。