Identifiability of discrete-time linear switched systems

In this paper we study the identifiability of linear switched systems (LSSs) in discrete-time.The question of identifiability is central to system identification, as it sets the boundaries of applicability of any system identification method; no system identification algorithm can properly estimate the parameters of a system which is not identifiable. We present necessary and sufficient conditions that guarantee structural identifiability for parametrized LSSs. We also introduce the class of semi-algebraic parametrizations, for which these conditions can be checked effectively.