Advances in Mathematics of Communications (AMC)

LDPC codes associated with linear representations of geometries

Pages: 405 - 417, Volume 4, Issue 3, August 2010      doi:10.3934/amc.2010.4.405

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Peter Vandendriessche - Boudewijn Hapkenstraat 5, 8820 Torhout, Belgium (email)

Abstract: We look at low density parity check codes over a finite field $\mathbb K$ associated with finite geometries $T$2*$(\mathcal K)$, where $\mathcal K$ is any subset of PG$(2,q)$, with $q=p$h, $p$≠char$\mathbb K$. This includes the geometry $LU(3,q)$D, the generalized quadrangle $T$2*$(\mathcal K)$ with $\mathcal K$ a hyperoval, the affine space AG$(3,q)$ and several partial and semi-partial geometries. In some cases the dimension and/or the code words of minimum weight are known. We prove an expression for the dimension and the minimum weight of the code. We classify the code words of minimum weight. We show that the code is generated completely by its words of minimum weight. We end with some practical considerations on the choice of $\mathcal K$.

Keywords:  LDPC codes, linear codes, finite geometry, linear representation, minimum distance, dimension.
Mathematics Subject Classification:  Primary: 51E15, 51E20, 94B05.

Received: December 2009;      Revised: May 2010;      Available Online: August 2010.