On the common structure of several well-known methods for harmonic analysis a direction-of-arrival estimation induced by a new version of ESPRIT

It is shown that several recently developed methods for direction-of-arrival estimation by an array of doublets (or for harmonic analysis) are in fact special cases of a more general method. Specifically, it is suggested that ESPRIT (estimation of signal parameters via rotational invariance techniques), the Toeplitz approximation method, Tufts and Kumanesan´s (1982, 1983) method, and variants of these methods can all be viewed as relying on the solution of the same multidimensional linear system. Each method corresponds to a different least-squares approach to the solution of the system. Among these, the total least-squares approach plays an especially important part