Inequivalence of Nega-cyclic ±1 Matrices

R. Ang, University of Wollongong
J. Seberry, University of Wollongong
T. A. Wysocki, University of Wollongong

Article comments

This article was originally published as Ang, R, Seberry, J and Wysocki, TA, Inequivalence of Nega-cyclic ±1 Matrices, Journal of Combinatorial Mathematics and Combinatorial Computing 56, 2006, 17-32.

Abstract

We study nega-cyclic ±1 matrices. We obtain preliminary results which are then used to decrease the search space. We find that there are 2, 4, 9, 23, 63, and 187 ip-equivalence classes for lengths 3, 5, 7, 9, 11, and 13 respectively. The matrices we find are used in a variant given here of the Goethals-Seidel array to form Hadamard matrices, the aim being to later check them for suitability for CDMA schemes.