APPROXIMATIONS TO THE CRAMER-RAO LOWER-BOUND ON FREQUENCY ESTIMATES FOR COMPLEX SINUSOIDS IN THE PRESENCE OF SAMPLING JITTER

It is argued that, in many cases of practical interest, the Cramer-Rao lower bound on frequency estimates for a short data record comprising multiple well-separated cisoids, or pairs of closely spaced cisoids, in complex white Gaussian noise, and in the presence of sampling uncer tainty, or jitter, may be approximated by a simple modification to the straightforward expression for the bound for an isolated single cisoi d subject to the same jitter. The approximations yield simple, closed- form results which illuminate the role played by each of the various p arameters.