Zero-redundancy coding for unequal code symbol costs

Source distributions that can be encoded with zero redundancy for the case of unequal code symbol costs are examined. These distributions provide a natural generalization of the binary, equal costs case for which these distributions are the dyadic distributions. These zero redundancy codes have the property that the expected proportion of codeword symbols given by a particular letter is equal to an experimental function of the code letter cost. The converse is not true in general; however, partial converse results hold. Maximum-entropy zero-redundancy distributions are easily identified through their connection with unequal cost coding for uniform sources.< >