在现代电子对抗和通信侦察中,共信道通信信号的调制模式识别是重要的研究课题。经验模态分解(EMD)是一种处理非平稳信号的新方法,但标准EMD方法存在模式混叠问题。文中提出了一种基于EMD分解与希尔伯特变换相结合的调制识别新算法,通过在EMD分解过程中多次添加掩蔽信号,用于共信道混合信号的分离,并讨论了所添加的掩蔽信号能够消除模式混叠现象需满足的必要条件。计算机仿真结果表明,该方法对频谱不混叠的单载波混合信号有较好的分离和调制识别效果。

The modulation mode recognition of co-channel signals is an important issue in modern electronic countermeasure and communication reconnaissance. The empirical mode decomposition provides a new method for signal processing from a non-stationary viewpoint, but one of the major drawbacks is mode mixing. A new method based on EMD method combined with Hilbert transform for modulation recognition was presented in this paper, that is, inserting different masking signals for several times during the decomposition process of co-channel signals. In the end, the necessary conditions of masking signal were also pointed out. The experimental results show that the proposed method performs well in single carrier signal separation and modulation recognition.