Resolution Ability of Fractional Fourier Transform in Multi-Component LFM Signal Chirp-Rate

Detecting and estimating multi-component LFM signal based on fractional Fourier transform (FrFT) becomes a hot field in recent years. In most situations, it will come across multi-component LFM signal with similarly parameters in signal processing. This means illegibility occurs in time-frequency analysis and there is a problem about resolution ability. During to this problem, when multi-component LFM signal has only one center frequency, the expression of resolution ability in chirp-rate based on FrFT is deduced. What´s more, the influence of the sampling time, sampling frequency and chirp-rate upon the resolution ability is analyzed and simulated. Finally, simulation results and analysis indicate that the resolution ability is mainly dependent on the biggest value of chirp-rate, and has the positive exponential relationship about with chirp-rate.