PAPR Reduction in MC/DS CDMA System by DFT Spreading Codes

Multi-carrier direct sequence code division multiple access (MC/DS CDMA) technique is one of the optimum technique for the reverse link mobile transmission. However, because of multi-carrier property, large PAPR (peak to average ratio) may be generated in MC/DS CDMA system. In this paper, DFT spreading code is applied to reduce high PAPR efficiently. As results, about 6dB PAPR can be achieved at CCDF of 10^-3. in the MC/DS CDMA system with 12 data carriers. SER performance can be improved significantly compared with conventional MC/DS CDMA system with nonlinear HPA.