Indecomposable Channels with Side Information at the Transmitter

In this paper the direct part and the strong converse of the coding theorem for two classes of Finite State Indecomposable Channels with Side Information at the Transmitter are proven. The question of membership in the first class can always be easily settled; to show that a channel belongs to the second class requires in general an infinite number of operations. A finite test is developed that is applicable if the given channel satisfies either of two additional restrictions. Fortunately, the second of these will be met by any “practical≓ indecomposable channel.