Coding for a class of unknown channels

A channel which is selected for each use (without knowledge of past history) to be one of a given set of discrete memoryless channels is to be used by an ignorant communicator, i.e., the transmitter and receiver are assumed to have no knowledge of the particular channels selected. For this situation an upper bound on the insurable average error probability for block codes of length n is obtained which exponentially approaches zero for all rates less than capacity. Communication design techniques for achieving these results are discussed.