2-DIMENSIONAL POLYNOMIAL PHASE SIGNALS - PARAMETER-ESTIMATION AND BOUNDS

This paper considers the problem of parametric modeling and estimation of nonhomogeneous two-dimensional (2-D) signals. In particular, we fo cus our study on the class of constant modulus polynomial-phase 2-D no nhomogeneous signals. We present two different phase models and develo p computationally efficient estimation algorithms for the parameters o f these models. Both algorithms are based on phase differencing operat ors. The basic properties of the operators are analyzed and used to de velop the estimation algorithms. The Cramer-Rao lower bound on the acc uracy of jointly estimating the model parameters is derived, for both models. To get further insight on the problem we also derive the asymp totic Cramer Rao bounds. The performance of the algorithms in the pres ence of additive white Gaussian noise is illustrated by numerical exam ples, and compared with the corresponding exact and asymptotic Cramer- Rao bounds. The algorithms are shown to be robust in the presence of n oise, and their performance close to the CRB, even at moderate signal to noise ratios.