提取循环平稳信号特征频率的方法

低阶循环统计量应用广泛，取得了很好的研究成果，但对噪声的抑制效果较差；高阶循环统计量虽能完全抑制高斯噪声的影响，能处理循环平稳、非线性、非高斯过程，但计算量大；循环自相关函数切片谱图能够提取出调制频率，但在较大噪声干扰时效果不明显。为在更低信噪比情况下，采用更快速方法提取出循环平稳信号的特征频率，采用循环双谱的载波频率切片谱提取所需频率。通过Matlab仿真和实验对比研究，发现在信噪比为-15 dB时，循环双谱的载波频率切片谱能直观表达出分析结果。

Methods for extracting characteristics frequency of cycle stationary signal

The low order cyclic statistics is widely applied with good results, but it has poor effect of noise suppression. The high-order cyclic statistics can suppress Gaussian noise, handle the cyclostationary, nonlinear and non-Gaussian process, but it has very large amount of calculation. Cyclic autocorrelation slice function can extract modulation frequency from the spectrum, but the effect is not obvious under large noise interference. In order to extract the characteristic frequency of cyclostationary signal in a lower Signal-to-Noise Ratio(SNR) and a more rapid calculation speed, carrier frequency slice spectrum of cyclic bispectrum method is adopted to extract the required frequencies. After simulation in Matlab and experimental research, it is found that the carrier frequency slice spectrum of cyclic bispectrum can still be expressed intuitively when the SNR is -15 dB.