The existence and the uniqueness of Augustin center and the associated Erven-Harremoes bound are established for arbitrary channels with convex constraint sets and finite Augustin capacity. Concepts of Augustin-Legendre capacity, center and radius are introduced and their equality to the corresponding Renyi-Gallager concepts is established. Sphere packing bounds with polynomial prefactors are derived for codes on two families of channels: (possibly non-stationary) memoryless channels with multiple additive cost constraints and stationary memoryless channels with convex constraints on the empirical distribution of the input codewords.
['Barış Nakiboğlu']
The Augustin Center and The Sphere Packing Bound For Memoryless Channels