PAPR reduction in FBMC systems using a smart gradient-project active constellation extension method

The filter bank multicarrier (FBMC) modulation scheme has recently seen renewed interest and is being considered as a viable alternative to orthogonal frequency division multiplexing (OFDM). FBMC, however suffers from the same high peak-to-average power ratio (PAPR) drawback as OFDM systems. Conventional OFDM PAPR reduction techniques cannot be directly applied to FBMC due to the overlapping nature of FBMC symbols. A novel technique is proposed based on an evolution of the smart-gradient project active constellation extension (SGP-ACE) PAPR reduction method used for OFDM systems, namely the FBMC SGP-ACE method. The proposed method is applied to a set of contiguous FBMC symbols, thereby compensating for the overlapping nature of FBMC modulation. The proposed method requires less iterations than a projection-onto-convex-sets (POCS) ACE approach to converge to a lower PAPR and significant reduction in complexity can be achieved as opposed to current FBMC PAPR reduction techniques which tend to require the addition of advanced signal processing. The proposed FBMC SGP-ACE method outperforms a conventional FBMC POCS-ACE method by 2.6dB in PAPR reduction at a clip probability of 10-4 on the 1st iteration.