一种高分辨自适应信号时频表示

Time-frequency representation of a high resolution adaptive signal

提出了一种采用线性调频窗函数的自适应短时傅里叶变换（Ｓｈｏｒｔ Ｔｉｍ ｅ ＦｏｕｒｉｅｒＴｒａｎｓｆｏｒｍ ，ＳＴＦＴ） 方法，利用时间－时延－多普勒函数（Ｔｉｍ ｅ－Ｌａｇ－Ｄｏｐｐｌｅｒ Ｆｕｎｃｔｉｏｎ，ＴＬＤＦ）和Ｒａｄｏｎ 变换技术估计信号的瞬时调频指数，并自适应地调整窗函数的参数，获得了高分辨率的时频表示．与现有的自适应ＳＴＦＴ方法相比，该方法是一种开环的计算方法，避免了非线性优化和迭代运算．

This paper presents a method of adaptive short time Fourier analysis (STFT) with linear frequency modulation window functions. The chirp rate of the window function is adaptively adjusted via the Time Lag Doppler function (TLDF) and the Radon transform, and a high time frequency resolution is achieved. Compared with current adaptive methods, this method is an open loop algorithm, which avoids nonlinear programming and iterative computation. Experiment results prove the validity of this method.