A new interference cancellation technique for synchronous CDMA communication systems using modified prime codes

A new technique of interference cancellation for synchronous optical CDMA communication systems is proposed We utilized the properties of modified prime sequences under the assumption of a Poisson shot noise model for the PIN photodiode and synchronization between users´ symbols. The interference cancellation technique is based on estimating the multiuser interference (MUI) through the special correlation properties of the used codes. The estimated MUI is then used to adapt a threshold level to optimally detect the concerned user´s information and to suppress the MUI. Detailed derivations of the closed forms for the bit error rate are presented for both cases of with and without the suggested MUI suppression. Numerical results clearly show the advantages of the proposed technique and proves that it outperforms a system without interference cancellation