BER Performance of MC DS-CDMA with Frequency-domain Equalization

Abstract Multi-carrier direct sequence code division multiple access (MC DS-CDMA) is a combination of time-domain spreading and orthogonal frequency division multiplexing (OFDM), while multi-carrier code division multiple access (MC-CDMA) is a combination of frequency-domain spreading and OFDM. In MC-CDMA, a good bit error rate (BER) performance can be achieved by using frequency-domain equalization (FDE), since the frequency diversity gain is obtained. On the other hand, conventional MC DS-CDMA cannot obtain the frequency diversity gain. In this paper, we propose MC DS-CDMA that can obtain the frequency diversity gain by applying FDE to a block consisting of a number of OFDM symbols. The conditional BER analysis is presented. The theoretical average BER performance in a frequency-selective Rayleigh fading is evaluated by Monte-Carlo numerical computation method using the derived conditional BER and is confirmed by computer simulation of the MC DS-CDMA signal transmission. Keyword MC DS-CDMA, frequency-domain equalization, frequency diversity gain