Resumen
In this paper, the possibilities of expressing the natural response of a linear commensurate fractional-order system (FOS) as a linear combination of basis functions are analyzed. For all possible types of sa-domain poles, the corresponding basis functions are found, the kernel of which is the two-parameter Mittag?Leffler function Ea,ß, ß = a. It is pointed out that there are mutually unambiguous correspondences between the basis functions of FOS and the known basis functions of the integer-order system (IOS) for a = 1. This correspondence can be used to algorithmically find analytical formulas for the impulse responses of FOS when the formulas for the characteristics of IOS are known. It is shown that all basis functions of FOS can be generated with Podlubny?s function of type ek (t, c; a, a), where c and k are the corresponding pole and its multiplicity, respectively.