Reduced complexity tone reservation peak-to-average power ratio reduction algorithm for SEFDM signals

A reduced complexity tone reservation peak-to-average power ratio (PAPR) reduction method for multicarrier signals with nonorthogonal frequency spacing (Spectrally Efficient Frequency Division Multiplexing, SEFDM) is proposed. It is based on the modification of Tone Reservation method and suits for big number of subcarriers: 1024-32768. It is proposed to use a small part of the frequency band gain obtained by SEFDM signals to reduce PAPR with no need to send side information to receiver. In the proposed algorithm additional subcarriers for PAPR reduction are equally spaced over the signal bandwidth with randomly generated different combinations of manipulation symbols. The PAPR reduction in average is of 1.8 dB for 840 subcarriers, and 1.2 dB for 27841 subcarriers. The degree of reduction of the PAPR depends on the amount of additional subcarrier channel alphabet and on the number of attempts of generation of additional subcarrier symbol combinations. Complexity issues for the proposed PAPR reduction algorithm are also considered: simple low additional resource approach based on reduced size IFFT blocks is recommended.