IEEE Transactions on Automatic Control, Vol.46, No.2, 314-319, 2001
On formal power series representations for uncertain systems
The concept of minimality as developed for uncertain and multidimensional systems represented by linear fractional transformations (LFTs) is related to realization theory results for formal power series. We discuss the relationship between the notions of minimality for LFT and series realizations, and present a method for obtaining one type of minimal realization from the opposing type. An extension of an existing minimality result for formal power series to the multi-input-multi-output (MIMO) case is also presented.