Abstract:

An approach for parameters estimation of linear frequency modulation (LFM) signals by interpolation based on fractional Fourier transform (FRFT) is investigated. Firstly, in order to obtain the accurate estimate of α,an interpolation method using coefficients of DFRFT under the condition of a bigger search step is proposed. Then, according to the gate effect problem because of discretization of u,the interpolation on digitalFRFT spectrum lines is also used to improve the estimate accuracy of u. Finally, the results of estimation of αand uare used to estimate the parameters of single component LFM signal. The new interpolation based on  FRFTcan reduce the computational complexity, and at the same time, the accuracy of estimation is improved. Simulation resultindicates that the root-mean-square error of parameter estimation is still approaching the Cramer-Rao bound (CRB) under the condition of low  signal-to-noise ratio (SNR).