Performance of multicarrier DS-CDMA systems with time-limited chip waveforms

This paper studies the effect of time-limited chip waveform shaping on the performance of multicarrier direct-sequence code division multiple access (MC-DS-CDMA) systems. The performance criterion is the average multiple access interference (MAI) at the output of a correlation receiver. Comparison among different chip waveforms is made based on a fixed bit rate and a fixed total bandwidth, where the fractional out-of-bandpower (FOBP) definition is used. It is demonstrated that, compared to the performance of single-carrier DS-CDMA (SC-DS-CDMA) systems, the performance of MC-DS-CDMA systems is less sensitive to the chip waveform shaping. Moreover, the relative performance of MC-DS-CDMA systems using different time-limited chip waveforms depends heavily on the bandwidth definition and is also very different compared to that of SC-DS-CDMA systems.