Abstract
Although multiple access interference (MAI) problems existing in optical code division multiple access (OCDMA) systems can be solved by electrical subtraction, phase induced intensity noise (PIIN) resulting from the phase incoherent of overlapping still remains and completely deteriorates the system performance. It is therefore desirable to alleviate MAI and PIIN effects in designing OCDMA system. We propose a new method to construct codes with zero in-phase cross correlation namely Zero Vector Combinatorial Code (ZVCC) based on combination of specific vectors with combinatorial theories. Simplicity of code construction, flexibility of choosing the number of users and weights, make our proposed system strong candidate for future networks. In addition, transmitter side and receiver side are proposed. Detailed examples are given on how to pick the best code among different options based on specific parameters. The results show that the proposed code is effective to reduce the MAI, PIIN and cost, while maintaining a good signal to noise ratio and bit error probability. A comparison study between the proposed code and the existing codes such as Hadamard and MDW has been carried out.