提出了光域隐藏通信的概念以及评价其性能的指标：隐藏性、可用性和稳健性,给出了基于现有光纤通信体制的三种光域隐藏通信方案及其对系统配置的要求。使用光纤通信系统仿真软件对所提出的方案进行了仿真研究,针对现有的光纤宿主信道的特点,提出了采用码移键控(CSK)平衡调制方式和基于等效相移超结构光纤光栅(EPS-SSFBG)双边带编/解码器的系统配置方案以提高系统的性能。结果表明,该方法各项性能指标良好。在信噪比为-13 dB,信号完全隐藏在信道噪声中的情况下,仍然能够以1.25 Gb/s的速率保持通信,能够抑制隐藏系统与宿主系统间的相互影响,是一种具有较高应用价值的光域隐藏通信方法。

The concept of covert communication in optical domain and its performance estimation indexes of imperceptibility, usability, and robustness were illuminated. The method of optical domain covert communication based on coherent optical code division multiple access (OCDMA) technology was analyzed. Three covert schemes and their system configuration parameters were offered. Aiming at the properties of existing optical communication host channel, code-shift-keying (CSK) balance modulation and double side band en/decoder based on equivalent phase shift-superstructure fiber Bragg grating (EPS-SSFBG) were proposed to improve the performance of the system. The simulation results show that the proposed schemes can obtain a good performance. With signal-to-noise rate (SNR) of -13 dB, under the condition that the signal was completely covered by channel noise, and in this situation, the system still kept communication with a bit rate of 1.25 Gb/s, the inter-influence between covert signal and host signal was suppressed.