OFDM雷达信号子载波调制方式识别方法

A Modulation Mode Identification Method of Subcarrier for OFDM Radar Signals

针对多径信道下传统方法识别OFDM雷达信号子载波调制方式存在识别正确率较低,识别子载波调制方式不完备,判决门限不易确定等问题,提出一种新颖的OFDM雷达信号子载波调制方式识别方法。利用OFDM雷达信号的瞬时幅度绝对值标准偏差,实现子载波多进制正交振幅调制(MQAM)和多进制相位调制(MPSK)的类间识别,利用组合高阶累积量作为识别特征量,对MQAM和MPSK两类调制方式中的子类间进行分类识别,利用递归降价的方法实现子载波调制阶数M>16的MQAM调制方式的识别。仿真实验结果表明,该方法能够有效实现多径信道下OFDM雷达信号多种子载波调制方式的识别,且识别性能更优,可以识别更完备的子载波调制方式类型。

In order to overcome the lower recognition accuracy,the incomplete recognition subcarrier modulation mode and uneasy determination of judging threshold problem of the traditional subcarrier modulation recognition method for OFDM radar signals in the multipath channel,a novel subcarrier modulation recognition method for OFDM radar signals is proposed.Firstly,the standard deviations of OFDM radar signals’absolute value of instantaneous is used to indentify the modulation type between MQAM and MPSK.Secondly,the combination of high order cumulant is used as identification feature to make classification and identification among the subclasses in MQAM and MPSK modulation mode.Finally,the recursive order-reduction algorithm is utilized to recognize the higher-order modulation type MQAM(M>16).The simulation experimental results show that the proposed method can effectively recognize many kinds of modulation mode of subcarrier for OFDM radio signals under multipath channel with more superior identification performance rate and can reidentify more complete subcarrier modulation modes and types.