多相码雷达信号识别与参数估计

Recognition and Parameters Estimation of Polyphase-coded Radar Signals

该文研究了多相码雷达信号的识别与参数估计。首先估计接收信号的码元宽度,利用多相码信号的时宽和码元宽度已知的条件下可以确定相位调制规律的特点,构造本地参考信号;把该参考信号与接收信号共轭相乘,当本地参考信号与接收信号的调制方式一致时共轭相乘的结果是正弦波,利用这个性质进行调制方式识别;估计该正弦波的频率作为载频估计;最后分析了存在同步误差时的频谱结构。仿真结果显示本算法可以在低信噪比条件下对多相码信号进行识别,并得到载频和码元宽度的精确估计值。

Recognition and parameters estimation of the polyphase-coded radar signals are discussed in this paper. First the code period of the received signals is estimated. When the pulse width and the code period are of prior knowledge, phase modulation of the polyphase-coded signals can be determinated, therefore the local reference signals can be generated and then multiplied with the conjugated received signals. When one of the local reference signals and the received signals had the same modulation mode, the result of multiplication is a sinusoid, thus the polyphase-coded signals can be classified and the carrier frequency can be obtained by estimating frequency of the sinusoid. Finally, the spectral structure is analyzed under asynchronous circumstance. Simulation results show that this method can recognize the polyphase-coded signals at low signal-to-noise ratio and estimate the carrier frequency and code period accurately.