Abstract :
A (v, k, λa, λc) optical orthogonal code (OOC) C is a family of (0, 1)-sequences of length v and weight k satisfying the following two correlation properties: (1) Σ0⩽t⩽v-1xtxt+i ⩽λa for any x=(x0,x1,···,xv-1 )∈C and any integer i not equivalent 0 mod v; and (2) Σ 0⩽t⩽v-1xtyt+i⩽λ b for any x=(x0,x1,···, xv-1) ∈ C, y=(y0,y1,···,yv-1) ∈C with x≠y, and any integer i, where the subscripts are taken modulo v. The study of optical orthogonal codes is motivated by an application in optical code-division multiple-access communication systems. In this paper, upper bounds on the size of an optical orthogonal code are discussed. Several new constructions for optimal optical orthogonal codes with weight k⩾4 and correlation constraints λa=λc=1 are described by means of optimal cyclic packings. Many new infinite series of such optimal optical orthogonal codes are thus produced
Keywords :
code division multiple access; codes; correlation methods; optical communication; optimisation; series (mathematics); set theory; code weight; code-division multiple-access; correlation constraints; correlation properties; infinite series; optical CDMA communication systems; optimal cyclic packings; optimal optical orthogonal codes; sequence length; sequence weight; set theory; Autocorrelation; Codes; Communication systems; Electronic mail; Laser radar; Modular construction; Multiaccess communication; Optical feedback; Optical fiber networks; Upper bound;
