A Novel Conversion Vector-Based Low-Complexity SLM Scheme for PAPR Reduction in FBMC/OQAM Systems

Filter bank multicarrier with offset quadrature amplitude modulation (FBMC/OQAM) is considered as a powerful supplementary waveform for future wireless communications. However, FBMC systems have the same high peak-to-average power ratio (PAPR) problem as other multi-carrier systems, and the PAPR reduction methods designed for orthogonal frequency division multiplexing (OFDM) systems cannot be directly applied to FBMC systems due to the unique overlapping structure of FBMC signals. Therefore, some PAPR suppression schemes tailored to FBMC systems have been proposed, but their computational complexity is prohibitively high for some practical applications. In this paper, we propose a conversion vector-based low-complexity dispersive selection mapping (DSLM) scheme, called the C-DSLM scheme, to reduce the PAPR of FBMC signals. In the C-DSLM scheme, a series of conversion vectors is first carefully designed for FBMC signals with overlapping structures, and then candidate signals are generated by multiplying the original signal by the cyclic shift of the conversion vectors with only a few nonzero elements. The complexity evaluation and simulation results show that the C-DSLM scheme's PAPR suppression performance is similar to that of the DSLM scheme with computational complexity is only approximately 10% of that of the DSLM scheme. Our proposed C-DSLM scheme is highly efficient and strongly applicable.