Two-dimensional frequency estimation using autocorrelation phase fitting

In this paper, the problem of two-dimensional (2-D) frequency estimation of a complex sinusoid embedded in a white Gaussian additive noise is addressed. A new frequency estimator based on a least square plane fitting of the estimated autocorrelation phase of the signal is derived. This algorithm requires a 2-D phase unwrapping step which can be easily done. This algorithm is shown to be unbiased and attains the Cramer Rao bounds for high signal to noise ratio ( ). Accuracy and robustness of this new 2-D frequency estimator are statistically assessed by Monte Carlo simulations. The results obtained show that a good local frequency estimation can be achieved with a very simple algorithm, and a very small amount of points used for the autocorrelation estimation.