Substitution of characters in q-ary m-sequences

  • István Vajda
  • Tibor Nemetz
Submitted Contributions Error Correcting Codes: Theory And Applications
Part of the Lecture Notes in Computer Science book series (LNCS, volume 508)


This paper discusses a simple way of increasing the linear complexity of maximal length q-ary sequences. This is attained by using character substitution tables. The achievable maximum of increase is determined and it is shown that a portion of about 1/e of all substitution tables share this maximum. The mean value and the variance of the linear complexity is derived for the sequence's output by randomly chosen substitutions. The special case of permutations as substitutions are investigated, as well. At the end of the paper we propose an extension of the notion of linear complexity.


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Copyright information

© Springer-Verlag Berlin Heidelberg 1991

Authors and Affiliations

  • István Vajda
    • 1
  • Tibor Nemetz
    • 2
  1. 1.Technical University of BudapestBudapest
  2. 2.Math. Inst. of the HASBudapest

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