A New Interpretation of Information Rate

Shannon defines the rate of transmission over a noisy communication channel in terms of various probabilities. 1 This definition is given significance by a theorem which asserts that binary digits may be encoded and transmitted over the channel at this rate with arbitrarily small probability of error. Many workers in the field of communication theoiy have felt a desire to attach significance to the rate of transmission in cases where no coding was contemplated. Some have even proceeded on the assumption that such a significance did, in fact, exist. For example, in systems where no coding was desirable or even possible (such as radar), detectors have been designed by the criterion of maximum transmission rate or, what is the same thing, minimum equivocation. Without further analysis such a procedure is unjustified. The problem then remains of attaching a value measure to a communi1 C. E. Shannon, A Mathematical Theory of Communication, B.S.T.J., 27, pp. 379-123, 623-656, Oct., 1948.