Bounds on the minimum distance of linear codes

Bounds on linear codes [248,9] over GF(4)

lower bound:171
upper bound:179


Construction of a linear code [248,9,171] over GF(4):
[1]:  [255, 16, 170] "BCH code (d = 170, b = 1)" Linear Code over GF(2^2)
     BCHCode with parameters 255 170
[2]:  [256, 16, 171] Linear Code over GF(2^2)
     ExtendCode [1] by 1
[3]:  [248, 9, 171] Linear Code over GF(2^2)
     Construction B of [2]

last modified: 2008-05-17

From Brouwer's table (as of 2007-02-13)

Lb(248,9) = 171 is found by construction B:
 [delete from a [256,16,171]-code
the (at most) 8 coordinates of a word in the dual]

Ub(248,9) = 179 is found by considering shortening to:
Ub(247,8) = 179 is found by considering truncation to:
Ub(245,8) = 177 DM4
DM4: R. N. Daskalov & E. Metodieva, The Linear Programming Bound for Ternary and Quaternary Linear Codes, preprint, Jan 2002.


  • All codes establishing the lower bounds were constructed using MAGMA.
  • Upper bounds are taken from the tables of Andries E. Brouwer, with the exception of codes over GF(7) with n>50. For most of these codes, the upper bounds are rather weak. Upper bounds for codes over GF(7) with small dimension have been provided by Rumen Daskalov.
  • Special thanks to John Cannon for his support in this project.
  • A prototype version of MAGMA's code database over GF(2) was written by Tat Chan in 1999 and extended later that year by Damien Fisher. The current release version was developed by Greg White over the period 2001-2006.
  • Thanks also to Allan Steel for his MAGMA support.
  • My apologies to all authors that have contributed codes to this table for not giving specific credits.

  • If you have found any code improving the bounds or some errors, please send me an e-mail:
    codes [at]

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