Capacity and decoding rules for classes of arbitrarily varying channels

The capacity of an arbitrarily varying channel (AVC) is considered for deterministic codes with the average probability of error criterion and, typically, subject to at state constraint. First, sufficient conditions are provided that enable relatively simple decoding rules such as typicality, maximum mutual information, and minimum distance, to attain capacity. Then the (possibly noisy) OR channels and group adder channels are studied in detail. For the former the capacity is explicitly determined and shown to be attainable by minimum-distance decoding. Next, for a large class of addictive AVCs, in addition to providing an intuitively suggestive simplification of the general AVC capacity formula, it is proven that capacity can be attained by a universal decoding rule. Finally, the effect of random state selections on capacity is studied. The merits and limitations of a previous mutual information game approach are also discussed