Contact:
Marcus Greferath
School of Math. Sciences
University College Dublin
Belfield, Dublin 4, Ireland
Phone:
+353-1-716-2588 (UCD)
+353-85-153-0951 (mobile)

Joachim Rosenthal
Institut of Mathematics
University of Zurich
Winterthurerstrasse 190
8057 Zurich, Switzerland
Phone:
+41-44-63 55884 (office)

ITW 2010 Dublin
IEEE Information Theory Workshop
Dublin, August 30 - September 3, 2010




Algebraic codes

Tue 31 Aug, 14.40-16.00, Room 3

Contributed session

Eeva Suvitie and Jyrki Lahtonen
On the Degree of the Inverse of Quadratic Permutation Polynomial Interleavers

Abstract: An integral component of a turbo code is a carefully designed interleaver. Interleavers based on quadratic permutation polynomials (modulo N) were introduced by Sun and Takeshita. They have several good properties and were selected to be used in a future cellular phone system. Ryu and Takeshita later initiated the study of the related deinterleavers. Here we extend this latter work and introduce a very efficient method for computing the (degree of the) lowest degree polynomial giving the deinterleaver. Our approach is based on combining two techniques. The Chinese remainder theorem allows us to study one prime factor of N at a time. Our other technique is to first present the inverse function as a power series, and then turn that power series to a low degree polynomial using a Gröbner basis of the ideal of polynomials vanishing modulo a prime power.
Tue 31 Aug, 14.40-15.00, Room 3

M. M. Nastasescu and A. R. Calderbank
The Projective Kerdock Code

Abstract: Certain nonlinear binary codes can be constructed as binary images of Z4-linear codes under the Gray map. Examples include the second-order Reed-Muller code and the Kerdock and Preparata codes. In this paper, we consider a new quaternary code which is an additive subcode of the Z4-linear Kerdock code. The Kerdock code is the direct sum of a one-dimensional quaternary code and the quaternary subcode examined in this paper. This paper calculates the weight distribution of the projective Kerdock code from which the weight distribution of the dual code can be computed. The dual code is a supercode of the quaternary Preparata code. The projective Kerdock code is used to construct a deterministic measurement matrix for compressed sensing. Numerical experiments are presented for sparse reconstruction using the LASSO that show improvement over random Gaussian matrices of the same size.
Tue 31 Aug, 15.00-15.20, Room 3

José Joaquín Bernal and Juan Jacobo Simón
Information sets for abelian codes

Tue 31 Aug, 15.20-15.40, Room 3

Joaquim Borges, Cristina Fernández-Córdoba, and Steven T. Dougherty
Additive Codes over Z2 x Z4

Abstract: We describe recent results for codes over Z2 x Z4 giving their connection to binary codes via a natural Gray map. We study Z2Z4 self-dual codes and we state the major results concerning these codes. We state several open questions and discuss possible avenues of research.
Tue 31 Aug, 15.40-16.00, Room 3

Back to previous page

Return to conference mainpage



Copyright 2009 Claude Shannon Institute. Contact shannon@ucd.ie