Constructions of two-dimensional optical orthogonal codes of weight three
Xiuling Shan, Lidong Wang, Yanxun Chang, Xiaomiao Wang
TL;DR
The work advances two-dimensional optical orthogonal codes by focusing on weight-3, λ=1 codes and delivering a unified suite of set-theoretic descriptions, improved bounds, and recursive constructions. It leverages holey designs (HGDDs, IHGDDs, SCHGDDs), n-cyclic GDPs, and Skolem/Langford-type sequences to build large, provably optimal 2-D OOCs and to determine Φ$(m\times n,3,1)$ across broad parameter regimes. The main theorem provides explicit deficits μ under several modular conditions, while auxiliary designs enable scalable inflation from small base blocks to large grids. The practical impact lies in enabling efficiently constructible, high-size 2-D OOCs suitable for OCDMA systems, with concrete constructions for many parameter sets.
Abstract
The study of optical orthogonal codes has been motivated by an application in an optical code-division multiple access system. This paper focuses on optimal two-dimensional optical orthogonal codes with autocorrelation and cross-correlation both equal to $1$. By examining the structures of $n$-cyclic group divisible packings and semi-cyclic incomplete holey group divisible designs, we present new combinatorial constructions for two-dimensional $(m\times n,k,1)$-optical orthogonal codes. As a consequence, the exact number of codewords of an optimal two-dimensional $(m\times n,3,1)$-optical orthogonal code is determined for any positive integers $m$ and $n$.
