一种改进MDCFT分辨率的方法

A Way of Improving the Resolution of Modified Discrete Chirp-Fourier Transform

针对修正离散线性调频傅里叶变换(MDCFT)主瓣宽,导致Chirp信号参数为非整数时识别误差大,具有分辨力较差的问题,提出MDCFT的离散采样模型,在此基础上分析了变换在非整数参数情况下的最大幅值采样的分布位置,并以此提出了采用分辨单元内目标偏移的估计方法。仿真表明在同样的信噪比环境下,提出的方法具有更好的参数估计精度和更平稳的估计误差。

To solve the issue that resolution of Modified Discrete Chirp-Fourier Transform worsens when parameters are none-integer, a continuous-to-discrete model of MDCFT was proposed, based on which analyses the position of maximum discrete absolute value of non-integer-parameter signal. Then gives the target-shift method. The simulation results prove that this method gives a much better resolution at the same SNR.