The Cramér-Rao lower bound for directions of arrival of Gaussian cyclostationary signals

The Cramer-Rao lower bound on the variance of estimates of directions of arrival, signal strengths, and carrier frequencies and phases of cyclostationary signals arriving at an array is considered. Numerical evaluations of the bound for the estimates of directions of arrival show that it can be orders of magnitude lower than the corresponding bound for stationary signals, despite the great number of unknown parameters in the former case. Comparisons with the mean squared error of direction estimates obtained by the cyclic least squares algorithm show that the bound is not overly optimistic. >