一种基于合作信号的卫星叠加隐蔽通信方法

A Satellite Covert Communication Approach Based on Overlay Cooperative Signal

针对宽带信号在卫星转发器中难以找到合适的掩护信号问题,提出了一种基于卫星转发器频谱占用情况的自适应卫星合作信号叠加隐蔽通信方法。首先采用频谱感知技术检测和估计当前卫星转发器占用频谱的中心频率、带宽、信号功率等参数,从而获得可用的掩护信号信息;然后根据上述信息设计对应的分割滤波器组参数信息,将原宽带隐蔽通信信号的频谱分割成与掩护信号频谱带宽相适配的多个子频谱,并将这些子频谱混频搬移到对应的中心频率,使得隐蔽通信信号的频谱完全隐藏在转发器当前的频谱环境中;最后在信关站移除合作的掩护信号,并通过设计的盲相位估计算法将分割的子频谱进行逆搬移和重新聚合,得到原宽带隐蔽通信信号。利用论文提出的卫星叠加隐蔽通信方法,可以使得宽带隐蔽通信信号自适应的隐藏在当前卫星转发器电磁频谱环境中,即使对方电子侦察设备发现部分分割的子频谱信号也无法解调出有用的通信信息。

To solve the problem of lock suitable cover signal spectrum for broadband signal transmission in satellite communication system,an adaptive satellite covert communication approach is proposed based on overlay cooperative signal to increase the security performance of transmit signal.Firstly,spectrum sensing technology is employed to detect and estimate the center frequency,bandwidth,signal power and other parameters of the cover signals in current satellite transponder to obtain the available cover signal spectrum information.Secondly,the parameters of the segmentation filter group are designed to divide the transmit signal spectrum into multiple sub-spectrums according to the cover signal spectrum information.The spectrum of the covert communication signal is completely hidden in the current spectrum environment of the transponder by modulating the sub-spectrums into the corresponding cover signal spectrums.Finally,the cooperative cover signal is removed at the gateway,and the divided sub-spectrums are reaggregated by the designed blind phase estimation algorithm to obtain the original broadband covert communication signal.For the proposed satellite overlay covert communication approach,the broadband covert communication signal can be adaptively hidden in the electromagnetic spectrum environment of the current satellite transponder.Even if parts of the sub-spectrums are detected by electronic measuring equipment,counterpart cannot demodulate useful information.