线性正则变换是一种重要的时频分析工具,它是傅里叶变换、分数阶傅里叶变换的推广,是更一般形式的信号变换。Wigner分布是经典的时频分布函数,具有较好的时频聚集性能。本文从线性正则变换与Wigner时频分布的关系入手,分析了线性正则变换的时频滤波原理,并在此基础上提出了基于线性正则变换的时频滤波方法,给出了滤波器参数的详细设计。仿真实验表明,该方法是时频域信号滤波的有效手段。
The linear canonical transform is a powerful tool of time-frequency analysis. It is the generalization of the Fourier transform and the fractional Fourier transform. In fact, the linear canonical transform can be considered as a general linear transform. The Wigner distribution function is a classic analysis method in time-frequency domain owing to high signal concentration. Starting with the relationship between the linear canonical transform and the Wigner dis- tribution, the theory of time-frequency filtering about the linear canonical transform is analyzed, a time-frequency fil- tering method based on the linear canonical transform is presented, and the parameter selection of the filter is discussed in detail. Simulation results show that the proposed method can effectively eliminate the noise of time-frequency signals.