Author :
Wu, Dianhua ; Zhao, Hengming ; Fan, Pingzhi ; Shinohara, Satoshi
Author_Institution :
Keylab of Inf. Coding & Transm., Southwest Jiaotong Univ., Chengdu, China
Abstract :
Variable-weight optical orthogonal code (OOC) was introduced by Yang for multimedia optical CDMA systems with multiple quality of service (QoS) requirements. In this paper, the upper bound on the size of variable-weight OOCs is improved, a cyclic t-(v, W, λ, Q) packing is introduced to construct a variable-weight OOC, an upper bound for the number of blocks of t-(v, W, λ, Q) packings is obtained, and an equivalence between optimal cyclic packing and optimal variable-weight optical orthogonal code is established. Recursive constructions for optimal 2-CP(W, 1, Q;v)s are also presented. By using skew starters and these constructions, infinite classes of optimal (v, W, 1, {1/2, 1/2})-OOCs are obtained for W = {3, 4}, and {4, 5}.
Keywords :
code division multiple access; multimedia communication; optical fibre networks; orthogonal codes; quality of service; multimedia optical CDMA systems; multiple QoS requirements; optimal cyclic packing; optimal variable-weight optical orthogonal codes; recursive constructions; skew starters; Bit error rate; Hamming weight; Mathematics; Multiaccess communication; Multimedia systems; Optical design; Optical feedback; Optical losses; Quality of service; Upper bound; Cyclic packing; optical orthogonal code; packing design; skew starter; variable-weight optical orthogonal code;
