Frequency-domain pre-equalization transmit diversity for DS-CDMA mobile radio

Recently, frequency-domain equalization has been attracting an attention for improving the single-carrier transmission (i.e. DS-CDMA) performance in a frequency-selective fading channel. In the case of uplink transmissions, the orthogonality among users´ signals is lost since each user´s signal goes through a different fading channel and hence, the use of frequency-domain equalization at the receiver cannot sufficiently improve the uplink transmission performance. 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 base station receiver to a close-to-frequency-nonselective channel. The BER performance with proposed frequency-domain pre-equalization transmit diversity is evaluated by computer simulation.