Covert wireless communications are unprecedentedly vital for security and privacy of individuals, government, and military bodies. Besides encryption, hiding signal transmission deeply under noise background highly proliferates the covertness in the physical layer. A deep signal hiding leads to a low interception probability at the interceptor but a poor data recovery at the receiver. To ensure both high covertness and high-fidelity recovery, massive and dense optical comb channels are utilized for deep denoising through the analog spectrum convolution. Using an external modulation-based optical frequency comb (OFC) and a single detection branch, the available optical comb channels can sustainably scale up by breaking or greatly mitigating physical bottlenecks on immense hardware and spectrum requirements. Thus, a striking signal-to-noise ratio (SNR) rise can be achieved for deep denoising. Combination of 1024 comb channels (the first parallel comb channel number beyond 1000) and the analog spectrum convolution enable a record SNR enhancement of 29 dB for a microwave signal with a 10.24 GHz bandwidth and a 10 Mbit/s data rate, which is deeply hidden below the in-band noises by 18 dB or even 30 dB in both the frequency and time domains. This method opens a new avenue for covert communications.

中文翻译：

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使用海量光梳通道进行深度去噪的隐蔽无线通信

隐蔽的无线通信对个人、政府和军事机构的安全和隐私至关重要。除了加密之外，在噪声背景下深度隐藏信号传输极大地增加了物理层的隐蔽性。深度信号隐藏导致拦截器处的拦截概率较低，但接收器处的数据恢复较差。为保证高隐蔽性和高保真恢复，大量密集的光梳通道通过模拟频谱卷积进行深度去噪。使用基于外部调制的光频梳 (OFC) 和单个检测分支，可用光梳通道可以通过打破或大大减轻巨大硬件和频谱需求的物理瓶颈来持续扩展。因此，深度去噪可以实现显着的信噪比 (SNR) 上升。1024个梳状通道（第一个超过1000个并行梳状通道数）和模拟频谱卷积的组合使具有10.24 GHz带宽和10 Mbit / s数据速率的微波信号的29 dB SNR增强创纪录，这是深藏不露的在频域和时域中均低于带内噪声 18 dB 甚至 30 dB。这种方法为秘密通信开辟了一条新途径。在频域和时域中，它都深深地隐藏在带内噪声之下 18 dB 甚至 30 dB。这种方法为秘密通信开辟了一条新途径。在频域和时域中，它都深深地隐藏在带内噪声之下 18 dB 甚至 30 dB。这种方法为秘密通信开辟了一条新途径。