中文摘要：

精确地估计线性调频（LFM）信号的中心频率和调频率值,在雷达信号处理中有着十分重要的作用.WVD变换具有估计线性调频信号的中心频率和调频率特性,但当存在多个线性调频分量时,交叉项会严重影响线性调频信号中心频率和调频率的估计.针对这一问题,本文提出了基于STTFD（时频分布尺度变换）的线性调频信号参数估计的方法,即在时频平面内对信号进行尺度变换,去除信号瞬时时间和相关函数延迟量的耦合,使线性调频信号的频率随时间变化呈线性分布变为不随时间变化的常数分布,再通过在时频平面内沿时间轴做FFT积累所得到的信号峰值位置来估计信号的中心频率和调频率参数值,并且对STFD的特性以及相关函数延迟量和尺度变换常数对STTFD的影响进行了详细的分析.在本文最后,通过仿真数据验证了STTFD的特性及其精确估计线性调频信号参数的有效性.

英文摘要：

The accurate estimation of the center frequency and the chirp rate of linear frequency modulated signal play an important role in radar signal processing.The WVD transform can show the characteristic of the center frequency and the chirp rate of linear frequency modulation signal,but the cross-term of signals deteriorates the precision of the estimation of the center frequency and the chirp rate.In order to estimate those parameters of signal better,this paper proposes a new method of the parameters estimarion of linear frequency modulated signal based on STrFD （the scale transform in time-frequency distribution plane）, by which the frequency of signal in time-frequency distribution plane by the scale-transform to remove the coupling effect between the signal time and the correlation function delay changes from the linear distribution along the time axis to the constant distribution along the time axis, then the center frequency and the chirp rate of linear frequency modulated signal can be estimated by the peak value position of signal acquired by doing FFT along the time axis in time-frequency distribution plane. At the same time, the analysis of the characteristic of STTFD and the effect of the scale-transform constant and the correlation function delay on STTFD is given. Finally, the simulation data confirms the characteristic of STrFD and the effectiveness of the parameters estimation of linear frequency mod- ulated signal based on STTFD.