中文摘要：

针对非合作通信系统中，多径信道下含有导频的正交频分复用（OFDM）信号子载波调制方式难识别的问题，提出了一种OFDM信号子载波调制方式识别的新方法．该方法首先运用4阶与2阶累积量的组合特征，去除OFDM子载波信号中的空载波信号，然后利用4阶累积量和6阶累积量的组合特征，滤除纯导频子载波信号和部分混有导频的调制子载波信号，最后基于改进的减法聚类方法，对提取出来的受导频影响较小的调制子载波信号进行调制方式识别．实验仿真结果表明，该方法在多径信道条件下具有稳健的识别性能。

英文摘要：

In view of modulation identification of subcarriers of orthogonal frequency division multiplexing （OFDM） signals with a pilot in a multipath channel is a difficult problem in the non-cooperation communications system, a novel method for recognition of the subcarriers modulation of OFDM signals is proposed. The method firstly removes the null carrier signals of the OFDM using the combination characteristic of fourth-order and second order cumulants, and then filters out the pure pilot subcarrier signals and some Of the modulated subcarrier signals with a pilot by the combination feature of fourth-order and sixth-order eumulants, Finally, it recognizes the modulated subcarrier signals which are less affected by pilots with the improved subtractive cluster method. Simulation results show that the proposed method has robust recognition performance in the multipath channel.