Abstract :
The analysis presented in the original paper (19TP67903, IEEE Trans. Communication Technology, vol. COM-15, pp. 23-31, February 1967) was not intended to apply to normal fast fading channels characterized by rapid phase and frequency variations. Instead, by assuming sufficient time or frequency separations between the digits within a character so that independent fading of digits could be attained, the analysis was valid, and applied to physically realizable channels.
