Frequency-domain Pre-equalization Transmit Diversity for MC-CDMA

Recently, multi-carrier code division multiple access (MC-CDMA) has been attracting much attention for the broadband wireless access in the next generation mobile communications systems. In the case of uplink transmissions, the orthogonality property among users’ signals is lost since each user’s signal goes through different fading channel and hence, multi-access interference (MAI) is produced, thereby significantly degrading the transmission performance compared to the downlink case. The use of frequency-domain equalization (FDE) at the receiver cannot sufficiently suppress the MAI. In this paper, we propose frequency-domain pre-equalization transmit diversity (FPTD), which employs pre-equalization using multiple transmit antennas with transmit power constraint, in order to transform a frequency-selective channel seen at a receiver to the frequency-nonselective channel. The BER performance with proposed frequency-domain pre-equalization transmit diversity is evaluated by computer simulation. Keywords— Pre-equalization, transmit diversity, MC-CDMA, frequency-domain equalization, frequency-selective channel