5 research outputs found

    Determination of sizes of optimal three-dimensional optical orthogonal codes of weight three with the AM-OPP restriction

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    In this paper, we further investigate the constructions on three-dimensional (u×v×w,k,1)(u\times v\times w,k,1) optical orthogonal codes with the at most one optical pulse per wavelength/time plane restriction (briefly AM-OPP 33-D (u×v×w,k,1)(u\times v\times w,k,1)-OOCs) by way of the corresponding designs. Several new auxiliary designs such as incomplete holey group divisible designs and incomplete group divisible packings are introduced and therefore new constructions are presented. As a consequence, the exact number of codewords of an optimal AM-OPP 33-D (u×v×w,3,1)(u\times v\times w,3,1)-OOC is finally determined for any positive integers v,wv,w and u≥3u\geq3

    Semi-cyclic holey group divisible designs with block size three and applications to sampling designs and optical orthogonal codes

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    We consider the existence problem for a semi-cyclic holey group divisible design of type (n,m^t) with block size 3, which is denoted by a 3-SCHGDD of type (n,m^t). When t is odd and n\neq 8 or t is doubly even and t\neq 8, the existence problem is completely solved; when t is singly even, many infinite families are obtained. Applications of our results to two-dimensional balanced sampling plans and optimal two-dimensional optical orthogonal codes are also discussed.Comment: arXiv admin note: substantial text overlap with arXiv:1304.328

    Optimal 22-D (n×m,3,2,1)(n\times m,3,2,1)-optical orthogonal codes and related equi-difference conflict avoiding codes

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    This paper focuses on constructions for optimal 22-D (n×m,3,2,1)(n\times m,3,2,1)-optical orthogonal codes with m≡0 (mod 4)m\equiv 0\ ({\rm mod}\ 4). An upper bound on the size of such codes is established. It relies heavily on the size of optimal equi-difference 11-D (m,3,2,1)(m,3,2,1)-optical orthogonal codes, which is closely related to optimal equi-difference conflict avoiding codes with weight 33. The exact number of codewords of an optimal 22-D (n×m,3,2,1)(n\times m,3,2,1)-optical orthogonal code is determined for n=1,2n=1,2, m≡0(mod4)m\equiv 0 \pmod{4}, and n≡0(mod3)n\equiv 0 \pmod{3}, m≡8(mod16)m\equiv 8 \pmod{16} or m≡32(mod64)m\equiv 32 \pmod{64} or m≡4,20(mod48)m\equiv 4,20 \pmod{48}

    Maximum ww-cyclic holely group divisible packings with block size three and applications to optical orthogonal codes

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    In this paper we investigate combinatorial constructions for ww-cyclic holely group divisible packings with block size three (briefly by 33-HGDPs). For any positive integers u,v,wu,v,w with u≡0,1 ( mod  3)u\equiv0,1~(\bmod~3), the exact number of base blocks of a maximum ww-cyclic 33-HGDP of type (u,wv)(u,w^v) is determined. This result is used to determine the exact number of codewords in a maximum three-dimensional (u×v×w,3,1)(u\times v\times w,3,1) optical orthogonal code with at most one optical pulse per spatial plane and per wavelength plane.Comment: 33 page

    Semi-cyclic holey group divisible designs with block size three

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    In this paper we discuss the existence problem for a semi-cyclic holey group divisible design of type (n,m^t) with block size 3, which is denoted by a 3-SCHGDD of type (n,m^t). When n=3, a 3-SCHGDD of type (3,m^t) is equivalent to a (3,mt;m)-cyclic holey difference matrix, denoted by a (3,mt;m)-CHDM. It is shown that there is a (3,mt;m)-CHDM if and only if (t-1)m\equiv 0 (mod 2) and t\geq 3 with the exception of m\equiv 0 (mod 2) and t=3. When n\geq 4, the case of t odd is considered. It is established that if t\equiv 1 (mod 2) and n\geq 4, then there exists a 3-SCHGDD of type (n,m^t) if and only if t\geq 3 and (t-1)n(n-1)m\equiv 0 (mod 6) with some possible exceptions of n=6 and 8. The main results in this paper have been used to construct optimal two-dimensional optical orthogonal codes with weight 3 and different auto- and cross-correlation constraints by the authors recently
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