基于改进瞬时特征参数的数字调制识别

Digital modulation recognition based on improved instantaneous characteristic parameters

自动调制识别作为非协作通信系统的关键技术,仍然是通信对抗领域的研究热点。在此背景下针对基于瞬时特征调制识别算法在低信噪比条件下识别率低、识别信号有限等问题,提出了一种基于改进瞬时特征参数调制识别算法。该算法首先在I/Q基带信号中提取6种改进瞬时特征参数,然后依据改进特征的区分度构建决策树分类器,最终结合仿真实验与特征理论值给出恰当的判决门限。仿真实验结果表明,当信噪比低至1 dB时,10种数字调制信号的平均识别率在92%以上。

As a key technology of non-cooperative communication system, automatic modulation identification is still a research hotspot in the field of communication countermeasures. In this context, aiming at the problems of low recognition rate and limited recognition signal of traditional instantaneous characteristic modulation recognition algorithm under the condition of low SNR, an improved instantaneous characteristic parameter modulation recognition algorithm is proposed in this paper. Firstly, six kinds of improved instantaneous feature parameters are extracted from the I/Q baseband signals. Then, a decision tree classifier is constructed based on the improved feature discrimination. Finally, the appropriate decision threshold is given by combining the simulation experiment and the theoretical value of feature. The simulation results show that when the SNR is as low as 1 dB, the average recognition rate of the 10 digital modulation signals is above 92%.