Performance of MC-DS-CDMA System in Rayleigh Fading Channel with Non-coherent Combining Schemes and MAI Interference

In this paper, we analyzed the multi – carrier direct sequence code division multiple access system when the received signal is divided into predetermined spreading sequences, and the sub bands are modulated over M carriers. Because of the unknown phase of the received signal at each sub-band the receiver cannot coherently combine the outputs of the correlators. We consider in this paper non-coherent combining scheme (equal gain combining) with MAI interferences. The calculation of the probabilities of detection and false alarm for both multicarrier (MC) and single carrier (SC) system in a Rayleigh fading channel demonstrated that the performances of the multicarrier system are better than those with single carrier system. Obtained results demonstrated that the suppression (or the mitigation) of appeared interferences is obtained by the increase of the number of system carriers.