Abstract: To quantify the degree of the information recoverability in the noisy channels, a concept of information fidelity is proposed. We reveal the intrinsic relationship between the information fidelity and the mutual information, and also recover the relationship between the information fidelity and the error probability of the information recovery methods. The theoretical analysis indicates that the maximum information fidelity can be used to characterize the optimal distribution of the transferred messages. Due to this characterization, we present the optimal information transfer problem based on the maximization of the information fidelity. Through the case of binary memoryless channel, we demonstrate the relationships among the maximum information fidelity, the channel capacity, and the optimal distribution of the transferred messages. The theoretical and numerical results imply that the calculation on the maximum information fidelity can be simpler than that on the channel capacity.

Key words: information transfer, information fidelity, mutual information, channel capacity, optimization problem