An Accurate Parameter Estimator for LFM Signals Based on Zoom Modified Discrete Chirp Fourier Transform

摘要

An accurate parameter estimation of chirp rate and initial frequency of the linear frequency modulation (LFM) signals based on zoom modified discrete chirp Fourier transform (MDCFT) is investigated. The first step of the proposed algorithm returns a coarse estimate of the parameter by addressing the maximum MDCFT coefficient of a LFM signal. The coarse estimate is refined by fine search named zoom MDCFT (Zoom-MDCFT) in the second step. Compared to traditional brute fine search approaches, Zoom-MDCFT method has merit in high efficiency because it utilizes more prior information about the MDCFT results, thus requiring fewer extra computations. Finally, computer simulations are conducted to evaluate the performance by comparison with the Cramer-Rao lower bound. The proposed estimator shows accurate and robust performance with the addition in the additive white Gaussian noise.