一种chirp信号快速参数估计算法

摘要

针对目前线性调频( chirp, LFM)信号参数估计算法运算量较大且估计参数较少的问题,在分析Radon-Wigner变换( RWT)和分数阶傅里叶变换( FrFT)应用于chirp信号参数估计的基础上,提出了一种基于Wigner-Ville分布( WVD )切片和FrFT的chirp信号参数估计新算法。该算法首先通过对观测信号两个WVD切片的计算估计出调频斜率,然后得到相应的Fr-FT阶数,最后利用一次FrFT估计出chirp信号的初始频率、初始相位和幅度等参数。整个算法只需三次FFT的计算量即可估计出chirp信号的四个参数。仿真实验表明了该算法能在低信噪比下实现chirp信号参数的快速有效估计。%In order to reduce the computation complexity of parameter estimation for chirp signals and increase the estimated parameters, a new algorithm based on Wigner-Ville distribution slice and fractional Fourier transform is presented through the application of chirp signals parameter estimation based on Radon-Wigner transform and fractional Fourier transform. Firstly, the fre-quency rate is estimated through two WVD slices of observation signals, and then getting the or-der of FrFT. Finally, the other parameters, including initial frequency, initial phase and ampli-tude, are estimated by once FrFT. The whole processing just needs three times of FFT computa-tion complexity and can estimate all the chirp signal parameters. Simulation results show that the algorithm can estimate the parameters of chirp signal quickly and effectively at low SNR.