Abstract: In view of?linear-frequency modulation radar system?target detection and ranging, the fractional Fourier transform instead of?matched filtering?to achieve pulse compression is proposed, and the theoretical model?based on the?sample?type?discrete fractional Fourier transforms is derived. In addition, the time-delay ambiguity occurring in the DFRFT is analyzed. The real time-delay of the radar target estimated by the phase difference between the spectrum peak and its side-lobe is put forward. The result is compared with a classic?pulse compression method match filtering which is applied in the radar target detection and ranging. It is observed that the resolution by using the DFRFT is the same as the pulse compression, and the complexity can be reduced by around a half.

Key words: match filtering, Discrete Fractional Fourier Transforms（DFRFT）, pulse compression, radar target detection

摘要： 针对线性调频体制雷达的目标检测与测距，提出采用离散分数阶Fourier变换实现脉压，推导基于采样型离散分数阶Fourier变换脉压方法的理论模型，对采用离散分数阶Fourier变换实现脉压时出现的时延模糊进行分析，提出用与谱峰相邻数据的相位差估计真实雷达目标的时延解决模糊问题。在雷达目标检测与测距中，基于离散分数阶Fourier变换与匹配滤波的脉压方法相比，距离分辨力相同，运算量降低近一半。

关键词: 匹配滤波, 离散分数阶Fourier变换（DFRFT）, 脉压, 雷达信号检测