In this thesis, a rate adaptive convolutionally coded orthogonal multicarrier direct sequence code division multiple access (DS/CDMA) system is considered. When the transmitter is provided with the channel state information, we use the SINR estimate and rate compatible punctured convolutional (RCPC) code for data rate adaptation. We show that the proposed rate adaptive convolutionally coded multicarrier DS/CDMA system can improve data throughput and get frequency diversity.