DocumentCode :
923067
Title :
Optimal source codes for geometrically distributed integer alphabets (Corresp.)
Author :
Gallager, Robert G. ; Van Voorhis, David C.
Volume :
21
Issue :
2
fYear :
1975
fDate :
3/1/1975 12:00:00 AM
Firstpage :
228
Lastpage :
230
Abstract :
Let P(i)= (1 - \\theta)\\theta^i be a probability assignment on the set of nonnegative integers where \\theta is an arbitrary real number, 0 < \\theta < 1 . We show that an optimal binary source code for this probability assignment is constructed as follows. Let l be the integer satisfying \\theta^l + \\theta^{l+1} \\leq 1 < \\theta^l + \\theta^{l-1} and represent each nonnegative integer i as i = lj + r when j = \\lfloor i/l \\rfloor , the integer part of i/l , and r = [i] mod l . Encode j by a unary code (i.e., j zeros followed by a single one), and encode r by a Huffman code, using codewords of length \\lfloor \\log _2 l \\rfloor , for r < 2^{\\lfloor \\log l+1 \\rfloor } - l , and length \\lfloor \\log _2 l \\rfloor + 1 otherwise. An optimal code for the nonnegative integers is the concatenation of those two codes.
Keywords :
Huffman codes; Source coding; Encoding; Entropy; Equations; Protocols; Source coding; Stochastic processes;
fLanguage :
English
Journal_Title :
Information Theory, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9448
Type :
jour
DOI :
10.1109/TIT.1975.1055357
Filename :
1055357
Link To Document :
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