Effect of cyclic prefix reduction on OFDM-CDMA systems

Orthogonal Frequency Division Multiplexing (OFDM) is a promising candidate for Multi-Carrier (MC) transmission. The combination of OFDM and Code Division Multiple Access (CDMA) referred to as OFDM-CDMA has drawn much interest in wireless communication systems. Inspite of its various beneficial qualities, the drawback includes the requirement of Cyclic Prefix (CP) to avoid interference between OFDM symbols. In this paper, we address the effect of CP length by evaluating the performance of two OFDM-CDMA systems l)MC-CDMA 2) MC-Direct Sequence(DS)-CDMA. Simulation results shows that MC-CDMA outperforms MC-DS-CDMA with reduced cyclic prefix length. Moreover, it was also found that spreading factor have significant effect on the performance after CP reduction.