Global frequency estimation using adaptive identifiers

Online estimation of the frequencies of a signal which is the sum of n sinusoidals with unknown amplitudes, frequencies and phases is made through yet another well-known and simple system theoretical tool-adaptive identifiers. Convergence of the proposed estimator is proved. The new frequency estimator is of 3n order, as compared to the order 5n - 1 resulting from Marino-Tomei observers. Results are demonstrated via simulation.