Yeminy Tomer, Sadot Dan, Zalevsky Zeev
Department of Electro-Optical Engineering, Ben Gurion University, Beer Sheva, 84105 Israel.
Opt Express. 2011 Oct 10;19(21):20182-98. doi: 10.1364/OE.19.020182.
We propose a method for covert fiber-optic communication in both frequency and time domains. The power spectral density of the pulse sequence bearing the information is spread in the frequency domain below the noise level by means of sampling. In addition, temporal phase encryption prevents the coherent addition of the various pulses in the frequency domain, further reducing the signal power spectral density. Thus, there is no need to transmit the signal within the bandwidth of a public user in order to spectrally conceal the signal. Temporal spreading of the pulse sequence is achieved by spectral phase encoding, resulting in a stealthy temporal and spectral transmission.
我们提出了一种在频域和时域进行隐蔽光纤通信的方法。承载信息的脉冲序列的功率谱密度通过采样在频域中扩展到噪声水平以下。此外，时间相位加密可防止频域中各个脉冲的相干叠加，进一步降低信号功率谱密度。因此，无需在公共用户的带宽内传输信号来在频谱上隐藏信号。脉冲序列的时间扩展通过频谱相位编码实现，从而实现隐蔽的时间和频谱传输。
