摘要
研究了基于多元信号假设检验的多相码雷达信号调制方式识别算法。首先对接收信号作傅里叶变换得到功率谱,然后对功率谱进行平滑,估计平滑之后功率谱的重心作为载频粗估计;接着进行相关运算把信号变换到基带,估计基带信号的码元宽度;由估计出的参数构造本地参考信号和相关接收机,最后运用最大似然准则对相关接收机的输出进行判决,选择最大输出所对应的参考信号作为接收信号的调制方式。仿真表明,本算法在低信噪比条件下具有良好的性能,-5 dB时识别正确率达到99%。该方法计算量较小,适合于雷达电子对抗应用。
The recognition of modulation mode on the polyphase-coded radar signals is discussed based on the M-ary hypothesis testing. Firstly, the power spectrum of the received signals is obtained by Fourier transform and then smoothed. The carrier frequency is coarsely estimated by calculating the centroid of the smoothed power spectrum. Then the signals are transformed to the baseband-modulated signals by correlation and the code period is estimated. With the estimated parameters of the carrier frequency and the code period the local reference signals can be generated and a correlation receiver can be designed. Finally, the decision is made based on the maximum likelihood criterion. The modulation mode of the reference signals generates the maximum output of the received signals. Simulation results show that the performance of the algorithm is good at low SNR. When SNR is --5 dB the rate of correct recognition is 99%. The computation load of the method is low and it is suitable for radar ELINT （Electronic intelligence）.
出处
《数据采集与处理》
CSCD
北大核心
2008年第3期265-269,共5页
Journal of Data Acquisition and Processing
关键词
多相码
最大似然准则
假设检验
电子对抗
polyphase-coded
maximum-likelihood criterion
hypothesis testing
electronic intelligence
