A DE-BPTS Algorithm for PAPR Reduction in FBMC-OQAM Systems

The partial transmit sequence (PTS) algorithm can be used to reduce the peak-to-average power ratio (PAPR) of filter bank multi-carrier offset quadrature amplitude modulation (FBMC-OQAM) signals, but there will be problems of high computational complexity and poor reduction effect. A differential evolution of bilayer partial transmit sequence (DE-BPTS) algorithm is proposed to greatly improve PAPR performance and reduce computational complexity of the system. The algorithm performs a bilayer phase factor search on the signal data block to expand search range of the phase factor, thereby improving the PAPR reduction performance. The first layer combines PTS algorithm considering the overlapping characteristics with DE algorithm to search for the phase factor, and the second layer searches for the data. The blocks are grouped, and the phase factor search is performed again. Since the number of data blocks is reduced after grouping, the computational complexity of the second layer optimization is also greatly reduced. Simulation results and computational complexity analysis show that PAPR values obtained by the proposed DE-BPTS algorithm are similar to optimal PAPR values obtained by the overlapping partial transmit sequence (OPTS) algorithm with the exhaustive method, and computational complexity is significantly lower in comparison with OPTS algorithm. It also has better PAPR reduction performance and lower computational complexity in comparison with other optimized PTS algorithms.