A rate adaptive convolutional coding method for multicarrier DS/CDMA systems

In this paper, a rate adaptive convolutional coding method for multicarrier direct sequence code division multiple access (DS/CDMA) systems is considered In order to accommodate a number of coding rates easily and make the encoder and decoder structure simple, we use the rate compatible punctured convolutional (RCPC) code. We obtain data throughputs at several coding rates by choosing the coding rate which has the highest data throughput in the SINR sense. To achieve maximum data throughput, a rate adaptive system based on the channel state information (the SINR estimate) is proposed. The SINR estimate is obtained by the soft decision Viterbi decoding metric. We show that the proposed rate adaptive convolutionally coded multicarrier DS/CDMA system can enhance spectral efficiency and provide frequency diversity.