Performance assessment of MC-CDMA systems in impulsive noise

In this paper, we consider the effect of impulsive noise on the performance of multicarrier code division multiple access (MC-CDMA) systems and analyze the performance by examining the MC-CDMA system model in time domain. We have discovered that conventional Walsh-code based MC-CDMA is less robust to the presence of impulsive noise than the corresponding direct sequence (DS) CDMA and multicarrier modulation based (MCM) systems. Furthermore, it is demonstrated that the performance of MC-CDMA depends strongly on the selection of the utilized spreading codes. A modified MC-CDMA structure, called MC-SI-CDMA, is proposed and investigated in impulsive noise that employs subcarrier interleaving (SI) to reduce the crosscorrelation between the time-domain MC-CDMA waveforms and the impulsive noise. Computer simulation results conducted to support our analysis indicate that the proposed MC-SICDMA system in impulsive noise can provide a performance improvement of 2.5 dB at a bit error rate (BER) level of 10−3 compared with the DS-CDMA system.