Exponential frequency correlation function and its application in Doppler shift estimation

A Doppler shift estimation problem of a noisy received signal consisting of multiple moving targets that have similar radial velocities is addressed here. Traditional Doppler shift estimation algorithms based on Fourier transform (FT) frequently exhibit low resolution. Here, an exponential frequency correlation function (EFCF) is proposed by introducing a sensitivity exponent p that controls its output signal‐to‐noise ratio (SNR) and velocity resolution into the expression of a classical frequency correlation function (FCF). On the basis of the proposed EFCF, a novel Doppler shift estimation algorithm can adaptively select the exponent of the EFCF to achieve the optimum Doppler shift estimation effect in an echo signal based on the elimination algorithm. Moreover, the proposed method is performed on the basis of the fast FT and product operation. Thus, it can be easily implemented. Numerical simulations demonstrate that the performance of the proposed method is significantly improved compared with the existing algorithms.