95 research outputs found
Remarks on low weight codewords of generalized affine and projective Reed-Muller codes
We propose new results on low weight codewords of affine and projective
generalized Reed-Muller codes. In the affine case we prove that if the size of
the working finite field is large compared to the degree of the code, the low
weight codewords are products of affine functions. Then in the general case we
study some types of codewords and prove that they cannot be second, thirds or
fourth weight depending on the hypothesis. In the projective case the second
distance of generalized Reed-Muller codes is estimated, namely a lower bound
and an upper bound of this weight are given.Comment: New version taking into account recent results from Elodie Leducq on
the characterization of the next-to-minimal codewords (cf. arXiv:1203.5244
Decoding of Projective Reed-Muller Codes by Dividing a Projective Space into Affine Spaces
A projective Reed-Muller (PRM) code, obtained by modifying a (classical)
Reed-Muller code with respect to a projective space, is a doubly extended
Reed-Solomon code when the dimension of the related projective space is equal
to 1. The minimum distance and dual code of a PRM code are known, and some
decoding examples have been represented for low-dimensional projective space.
In this study, we construct a decoding algorithm for all PRM codes by dividing
a projective space into a union of affine spaces. In addition, we determine the
computational complexity and the number of errors correctable of our algorithm.
Finally, we compare the codeword error rate of our algorithm with that of
minimum distance decoding.Comment: 17 pages, 4 figure
Weight enumerators of Reed-Muller codes from cubic curves and their duals
Let be a finite field of characteristic not equal to or
. We compute the weight enumerators of some projective and affine
Reed-Muller codes of order over . These weight enumerators
answer enumerative questions about plane cubic curves. We apply the MacWilliams
theorem to give formulas for coefficients of the weight enumerator of the duals
of these codes. We see how traces of Hecke operators acting on spaces of cusp
forms for play a role in these formulas.Comment: 19 pages. To appear in "Arithmetic, Geometry, Cryptography, and
Coding Theory" (Y. Aubry, E. W. Howe, C. Ritzenthaler, eds.), Contemp. Math.,
201
Generalized Reed-Muller codes and curves with many points
The weight hierarchy of generalized Reed-Muller codes over arbitrary finite
fields was determined by Heijnen and Pellikaan. In this paper we produce curves
over finite fields with many points which are closely related to this weight
hierarchy.Comment: Plain Tex, 11 page
On the Minimum Distance, Minimum Weight Codewords, and the Dimension of Projective Reed-Muller Codes
We give an alternative proof of the formula for the minimum distance of a
projective Reed-Muller code of an arbitrary order. It leads to a complete
characterization of the minimum weight codewords of a projective Reed-Muller
code. This is then used to determine the number of minimum weight codewords of
a projective Reed-Muller code. Various formulas for the dimension of a
projective Reed-Muller code, and their equivalences are also discussed.Comment: 24 pages; to appear in Adv. Math. Commun.; some typos corrected and a
reference added in this versio
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