A novel scheme for suppressing multi-user interference of optical CDMA system

Arming at the problem of multi-user interference existing in optical code division multiple access (CDMA) system, a novel scheme of suppressing multi-user interference in optical CDMA is presented. It can avoid the case no optical pulse existing while bit 0 is transmitted by adopting a spread spectrum code and its shift as address codes of bit 0 and bit 1, respectively, peak value decision instead of threshold decision is used in receiver to further reduce multi-user interference. The fundamental of it is set forth, optimal optical orthogonal codes are applied as address codes; bit error probability of novel system is derived and analyzed with APD as photo detector. Simulations based on the expression are done. The results show that bit error performance of the novel system can be several orders better than that of conventional system.