ACE with frame interleaving scheme to reduce peak-to-average power ratio in OFDM systems

High peak-to-average power ratio (PAPR) is one of the major limitations to orthogonal frequency division multiplexing (OFDM) systems. In an OFDM system, as the frame size increases, the PAPR probability performance will get worse. The so-called active constellation extension (ACE) algorithm has been proposed to effectively reduce the PAPR especially when the number of sub-carriers is large. To achieve low PAPR with small number of sub-carriers, a novel scheme, ACE with frame interleaving, is proposed in this paper. In our proposal, M frames with N sub-carriers will be combined into one super frame, then ACE algorithm is applied to reduce the PAPR of the super frame, the super frame with lowered PAPR will finally be divided into M OFDM frames for the transmission. The combining and dividing process is equivalent to the time interleaving. The proposed scheme requires no side information and can significantly reduce PAPR while maintaining small number of sub-carriers.