• 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