论文标题
经典欺骗电磁信号的量子限制
Quantum Limits to Classically Spoofing an Electromagnetic Signal
论文作者
论文摘要
欺骗电磁信号涉及测量其特性并准备一个足够近的副本以欺骗接收器的欺骗信号。欺骗的经典应用是在雷达中，空降目标试图通过发出表明脉冲或速度的脉冲来避免通过地面雷达跟踪。在某些情况下，已经显示传感器可以利用量子力学来检测单光子水平的欺骗。在这里，我们分析了一个理想化的欺骗场景，其中发射机收集器对寻求检测欺骗，利用从一组非正交的，连贯的状态随机选择的信号。我们表明，一家spoofer最佳地采用了有关传输信号状态的经典信息（即量子力学允许的最佳措施和培训策略）不可避免地会发出不完美的spoofs，而接收器可以利用，以揭示Spoofer的存在，或者揭示了真正的反思和欺骗。重要的是，我们表明，即使在较大的平均光子数量制度中，经典欺骗的量子限制仍然显着。
Spoofing an electromagnetic signal involves measuring its properties and preparing a spoof signal that is a close enough copy to fool a receiver. A classic application of spoofing is in radar where an airborne target attempts to avoid being tracked by a ground-based radar by emitting pulses indicating a false range or velocity. In certain scenarios it has been shown that a sensor can exploit quantum mechanics to detect spoofing at the single-photon level. Here we analyze an idealized spoofing scenario where a transmitter-receiver pair, seeking to detect spoofing, utilizes a signal chosen randomly from a set of non-orthogonal, coherent states. We show that a spoofer optimally employing classical information on the state of the transmitted signal (i.e. the best measure-and-prepare strategy allowed by quantum mechanics) inevitably emits imperfect spoofs that can be exploited by the receiver to reveal the presence of the spoofer, or to discriminate between true reflections and spoofs. Importantly, we show that the quantum limitations on classical spoofing remain significant even in the large mean-photon-number regime.
