Improvement of upper bound to the optimal average cost of the variable length binary code
We consider the optimal average cost of variable length source code averaged with a given probability distribution over source messages. The problem was argued in Csiszar and Korner's book [1]. In a special case of binary alphabet, we find an upper bound to the optimal cost minus an ideal cost, where the ideal cost is the entropy of the source divided by a. unique scalar that makes negative costs logarithmic probabilities. Our bound is better than the one given in the book.
average cost source coding variable length code balanced tree