Covert Wireless Communication with Enhanced Denoising Capability through a Dense Optical Frequency Comb

We proposed a covert wireless communication system enhanced with dense optical frequency comb (OFC) for denoising is proposed. Original data is spread with random phases, hidden below noise for high concealment and low interception probability in the microwave domain, then transmitted wirelessly. At the receiver, the signal is upconverted optically via carrier-suppressed single sideband modulation. An external modulation-based OFC with double sidebands is generated and used for denoising via analog spectrum convolution and in-phase coherent addition. This approach achieves a signal-to-noise ratio improvement of 10log(2xN) using N electric comb lines with special phases. Simulation results show 600 comb channels for in-phase summation and a 27 dB SNR increase with 300 electrical comb lines, demonstrating double detection gain without altering the OFC generation module.