ON THE IDENTIFIABILITY OF THE TIME-DELAY WITH LEAST-SQUARES METHODS

This paper investigates the presence and the effects of multiple minim a in the loss function to be minimized in time-delay estimation method s based on least squares. It is shown how in most cases a low-pass fil tering action is required on data used in the identification phase in order to estimate the proper delay value. The results presented are de rived by means of a frequency-domain interpretation of the least-squar es technique. The paper does not focus on a specific estimation algori thm, rather it presents a scenario to accommodate many recently publis hed identification methods. Some numerical examples illustrate the mai n results.