低频脉冲信号的频域恒虚警检测

为提高低频背景噪声中弱声呐脉冲信号的检测能力,给出了一种频域恒虚警检测方法。该方法针对低频背景噪声平稳性较差、起伏较大的特点,将频域中峰值点或极值点认为是疑似脉冲信号,通过对疑似点能量与历史背景进行比对的方式完成脉冲信号的检测判决,并且给出了相应的检验统计量获取方法、背景噪声估计方法和恒虚警检测门限的计算方法。仿真分析和实际数据处理结果表明,频域恒虚警检测方法对单频脉冲、单频-线性调频组合脉冲等包含窄带成分的弱声呐脉冲信号有非常好的检测性能。

Constant false alarm rate detection in frequency domain for low-frequency pulse

To improve the ability of detecting a weak sonar impulse signal form low-frequency background noise, a new detection method with constant false alarm rate (CFAR) in frequency domain is proposed. In this method, the peaks in the frequency domain are taken as the potential pulse signal due to the poor stability and large fluctuation of low-frequency background noise. Then, the detection decision is made through comparing the energy of those peaks and the energy of the background noise. The way of how to get statistic of test, background noise estimation and CFAR threshold is also given. Results of computer simulation and real data processing have confirmed the satisfactory performance of the proposed method in detecting weak sonar pulse signal like CW and CW-LFM, which contain narrow-band components.