Variable block length coding for channels with feedback and cost constraints

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (p. 95-96).Variable-decoding-time/generalized block-coding schemes are investigated for discrete memoryless channels (DMC) with perfect feedback (error free, delay free, infinite capacity) under cost constraints. For a given number of messages and average error probability, upper and lower bounds are found for expected decoding time. These coincide with each other up to a proportionality constant which approaches one in a certain asymptotic sense. A resulting reliability function is found for variable decoding time DMC's with perfect feedback under a cost constraint. The results in this work generalize Burnashev's results, to the cost constrained case.by Bariş Nakiboḡlu.S.M