Peak Power Reduction Method for MC-CDMA System

Peak power reduction is an important research topic for OFDM-based systems such as MC-CDMA. In this paper, we propose novel peak power reduction methods for time-domain spreading MC-CDMA systems. The block-scaling method, which reduces the peak power on a symbol-by-symbol basis, is very common. When applying it to time-domain spreading MC- CDMA systems, however, the power loss tends to be large because of the long symbol length. Our proposed method reduces the peak power on a chip-by-chip basis in order to mitigate the power loss compared to the Block-Scaling method. Moreover, by reallocating the reduced power by the method to low peak-power chips, the power loss becomes even smaller.