Performance of Multicarrier CDMA with Time-Frequency Spreading in Frequency Impairment Channels

In this paper the effect of carrier frequency offset on the multicarrier direct sequence CDMA system which employs both time and frequency (TF) domain spreading is evaluated and simulated. The MC DS-CDMA system achieves high spectrum efficiency by using time-frequency spreading mechanism. The probability of bit error rate (BER) of TF- domain spread MC DS-CDMA is derived using the standard Gaussian approximation (SGA) in additive white Gaussian noise (AWGN) channel with frequency offset impairments. Numerical evaluation of the analytical expression of BER reveals that a high capacity and BER performance improvement are achieved over the performance of multicarrier CDMA (MC-CDMA) system which spreads the signal in the frequency domain. Extensive simulations were also performed to illustrate the correctness of the analysis of the TF-domain spread MC DS-CDMA system.