多速率STFT超宽带信号瞬时频率估计研究

Research on Multi-rate STFT Algorithm in Instantaneous Frequency Estimation of Ultra Wide Band Signal[HS)]

摘要:

提出多速率短时傅里叶变换(Multi Rate Short Time Fourier Transform,MR-STFT)瞬时频率估计算法,提高了超宽带信号瞬时频率估计精度;该方法将多速率信号处理算法与短时傅里叶变换(STFT)技术相结合,兼顾采样频率和被测频率,将宽频范围进行分段采样,对分段处理结果进行拟合,构成多速率STFT算法,实现超宽带信号瞬时频率的高精度测量;通过对仿真信号和实测信号进行处理,研究了方法的可行性和频率估计精度,结果表明MR-STFT算法较大提高了超宽带信号瞬时频率估计精度,尤其对低信噪比的超宽带信号效果显著。

Abstract:

An instantaneous frequency estimation algorithm based on multi rate short time fourier transform (MR-STFT) is proposed to improve the instantaneous frequency estimation precision of ultra wide band (UWB) signal. This method combines multi-rate signal processing algorithm with short time fourier transform (STFT), taking into account the sampling frequency and the measured frequency, the wide frequency range is segmented sampling and each segment result is fitted with each other, the MR-STFT realizes the high precision measurement of the instantaneous frequency estimation of the UWB signal. The feasibility and the instantaneous frequency estimation precision of MR-STFT are studied by processing the simulation signal and the measured signal. The results show that MR-STFT algorithm greatly improves the instantaneous frequency estimation accuracy of UWB signal, especially for the UWB signal with low signal to noise ratio.