A Table of Bounds on Optimal Fixed-Length Ternary Edit-Metric Codes

 n\d 1 2 3 4 5 6 7 8 9 10 11 12
 1 3 1 1 1 1 1 1 1 1 1 1 1
 2 9 3 1 1 1 1 1 1 1 1 1 1
 3 27 9 3 1 1 1 1 1 1 1 1 1
 4 81 27 7 3  1  1  1  1  1  1  1  1
 5 243 81 15 5 3  1  1  1  1  1  1  1
 6 729 243  35-36 13 4 3  1  1  1  1  1  1
 7 2187 729 71-108 21-24 8 3 3 1  1  1  1  1
 8 6561 2187 179-324 41-72 15-24 7 3 3  1  1  1  1
 9 19683 6561 438-937 88-216 25-72 12-18 6 3 3  1  1  1
 10 59049 19683 1133-2811 202-648 49-216 18-54 9-14 5 3 3  1  1
 11 177147 59049 2972-7029 471-1944 98-648 29-162 11-36 7-12 4 3 3  1
 12 531441 177147 7819-19683 1129-5832 208-1557 56-486 20-108 10-36 7-9 4 3 3

The above table shows E3(n,d), the number of codewords in an optimal ternary code of fixed length n and minimum edit distance d. Where exact values are not known, upper and lower bounds are provided.

The earliest version of this table appeared in the technical report: S.K.Houghten, D.Ashlock and J.Lenarz, "Bounds on Optimal Edit-Metric Codes"and was ultimately published as "Construction of Optimal Edit Metric Codes", Proceedings of the 2006 IEEE Workshop on Information Theory (ITW 2006), 259-263.

Improvements since that time:

  1. E3(7,4) ≤ 24 and thus E3(8,4) ≤ 72, E3(9,4) ≤ 216, E3(10,4) ≤ 648, E3(11,4) ≤ 1944 and E3(12,4) ≤ 5832 (S.Houghten, August 2005)
  2. E3(6,3) ≥ 35 and E3 ≤ 36 and thus E3(7,3) ≤ 108 and E3(8,3) ≤ 324 (S.Houghten, August 2005)

If you have improvements, comments, etc, please e-mail shoughten@brocku.ca

This page last modified 22nd August 2005
© Copyright Sheridan Houghten, 2005