Research of algebra congruent codes used in two-dimensional OCDMA system

After summarizing the application of linear, quadratic, and hyperbolic operators in code-division multiple-access (CDMA) system, a generalized algebraic congruent code is presented by its construction formula in three different categories: frequency-hop (FH), time-spread (TS), and FH-TS codes. On the discussion of those three codes' auto- and cross-correlations and their contribution to bit-error-rate (BER) performances, a novel two-dimensional optical CDMA (OCDMA) system is provided in which different types of codes are used to provide different types of service. Such an OCDMA system is very fit for the case that a small part of services are high bit rate or high quality of service, while a great amount of services are not.