An investigation of peak-to-average power ratio in MC-CDMA combined with partial transmit sequence

摘要

The PAPR reduction in a synchronous downlink MC-CDMA using a PTS technique is investigated for different numbers of active users. The Walsh-Hadamard (WH) sequence and the orthogonal Gold (OG) sequence are used as the spreading sequences in the MC-CDMA system. From the simulation results, when the number of active users is varied, PAPR reduction of this system also varies depending on the PAPR characteristics of the spreading sequence. Although the PTS technique is very efficient in reducing PAPR, high PAPR reduction is achieved at a cost of increased system complexity. Furthermore, to compromise between PAPR reduction and system complexity, suboptimal algorithms are used for combining partial transmit sequences. Based on simulation results, we can reduce system complexity by more than 90% at the expense of little PAPR performance degradation.