Probing signals for model reference identification

This paper examines certain properties of probing signals employed in a model reference identification procedure which guarantee identification of the parameters of a linear multivariable system. The property of persistent excitation is examined with respect to a new class of (persistently spanning) signals. In particular, this class of signals includes many (periodic or almost periodic) signals which have previously been considered as effective probing signals, The results yield concrete guidelines useful in the practical design of probing signals.