直升机谐波信号的多频循环平稳检测

在直升机和无人机等目标的检测和识别方面,常用的方法没有充分利用目标信号的谐波特性,易受实战环境下强噪声和干扰的影响而降低检测能力.采用两个途径提高检测能力:利用谐波信号的相干特性,采用循环处理方法降低随机噪声和干扰的影响;采用频率分集分析和处理方法,将各阶谐波的循环平稳特征融合,提高抗干扰能力.计算结果表明,循环平稳处理方法可以正确的提取信号的频率特征;融合处理方法能在信噪比为2 dB甚至更低时检测谐波信号的循环平稳特征.该方法在多个领域具有较好的应用前景.

Multi-frequency Cyclostationary Analysis of Harmonic Signal of Helicopter

For the detection and identification of helicopters and UAV, the common methods do not take full ad-vantage of the harmonic characteristics of the target signals, and are vulnerable to environment noise and inter-ference on the battlefield,so the detection ratio is reduced Efforts to improve the detection ability are done in two ways:first,according to the coherence properties of harmonic signals, the cyclostationary analysis arithmetic is used to reduce the effect of the noise; second, the frequency diversity concept is used to analyze and fuse the harmonic signal feature. The results show that the cyclostationary analysis arithmetic can accurately extract the frequency characteristics of signals,and the fusion arithmetic can detect signal with SNR as low as 2 dB or even lower. This method has a good prospect in more application.