Throughput Improvement of STS-Based MC DS-CDMA System with Variable Spreading Factor

The throughput enhancement of space-time spreading (sts)-based multicarrierdirect sequence code division multiple access (mc ds-cdma) system is investigated inthis paper. variable spreading factor (vsf) is utilized to improve the data throughput ofthe system. in this contribution, an analytical approach is proposed to compute a newexpression for the bit error rate (ber) performance of the sts-based mc ds-cdmasystem against pre-dispreading signal-to-noise ratio (snr) for different values ofspreading factor (sf). the other contribution of the paper is deriving a new closed formexpression for computing the throughput enhancement and the ber performance of thevsf sts-based mc ds-cdma system over rayleigh fading channel. it is demonstratedthat using vsf method in sts-based mc ds-cdma system improves the throughput ofthe system by keeping the ber performance at the target level.