124 research outputs found
Toric surface codes and Minkowski sums
Toric codes are evaluation codes obtained from an integral convex polytope and finite field \F_q. They are, in a sense, a natural
extension of Reed-Solomon codes, and have been studied recently by J. Hansen
and D. Joyner. In this paper, we obtain upper and lower bounds on the minimum
distance of a toric code constructed from a polygon by
examining Minkowski sum decompositions of subpolygons of . Our results give
a simple and unifying explanation of bounds of Hansen and empirical results of
Joyner; they also apply to previously unknown cases.Comment: 15 pages, 7 figures; This version contains some minor editorial
revisions -- to appear SIAM Journal on Discrete Mathematic
Lattice polytopes in coding theory
In this paper we discuss combinatorial questions about lattice polytopes
motivated by recent results on minimum distance estimation for toric codes. We
also prove a new inductive bound for the minimum distance of generalized toric
codes. As an application, we give new formulas for the minimum distance of
generalized toric codes for special lattice point configurations.Comment: 11 pages, 3 figure
Toric surface codes and Minkowski length of polygons
In this paper we prove new lower bounds for the minimum distance of a toric
surface code defined by a convex lattice polygon P. The bounds involve a
geometric invariant L(P), called the full Minkowski length of P which can be
easily computed for any given P.Comment: 18 pages, 9 figure
Secret Sharing Schemes with a large number of players from Toric Varieties
A general theory for constructing linear secret sharing schemes over a finite
field \Fq from toric varieties is introduced. The number of players can be as
large as for . We present general methods for obtaining
the reconstruction and privacy thresholds as well as conditions for
multiplication on the associated secret sharing schemes.
In particular we apply the method on certain toric surfaces. The main results
are ideal linear secret sharing schemes where the number of players can be as
large as . We determine bounds for the reconstruction and privacy
thresholds and conditions for strong multiplication using the cohomology and
the intersection theory on toric surfaces.Comment: 15 pages, 4 figures. arXiv admin note: text overlap with
arXiv:1203.454
Small polygons and toric codes
We describe two different approaches to making systematic classifications of
plane lattice polygons, and recover the toric codes they generate, over small
fields, where these match or exceed the best known minimum distance. This
includes a [36,19,12]-code over F_7 whose minimum distance 12 exceeds that of
all previously known codes.Comment: 9 pages, 4 tables, 3 figure
AG Codes from Polyhedral Divisors
A description of complete normal varieties with lower dimensional torus
action has been given by Altmann, Hausen, and Suess, generalizing the theory of
toric varieties. Considering the case where the acting torus T has codimension
one, we describe T-invariant Weil and Cartier divisors and provide formulae for
calculating global sections, intersection numbers, and Euler characteristics.
As an application, we use divisors on these so-called T-varieties to define new
evaluation codes called T-codes. We find estimates on their minimum distance
using intersection theory. This generalizes the theory of toric codes and
combines it with AG codes on curves. As the simplest application of our general
techniques we look at codes on ruled surfaces coming from decomposable vector
bundles. Already this construction gives codes that are better than the related
product code. Further examples show that we can improve these codes by
constructing more sophisticated T-varieties. These results suggest to look
further for good codes on T-varieties.Comment: 30 pages, 9 figures; v2: replaced fansy cycles with fansy divisor
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