This paper presents four novel techniques for peak-to-average power ratio (PAPR) reduction in filter bank multicarrier (FBMC) modulation systems. The approach extends on current PAPR reduction active constellation extension (ACE) methods, as used in orthogonal frequency division multiplexing (OFDM), to an FBMC implementation as the main contribution. The four techniques introduced can be split up into two: linear programming optimization ACE-based techniques and smart gradient-project (SGP) ACE techniques. The linear programming (LP)-based techniques compensate for the symbol overlaps by utilizing a frame-based approach and provide a theoretical upper bound on achievable performance for the overlapping ACE techniques. The overlapping ACE techniques on the other hand can handle symbol by symbol processing. Furthermore, as a result of FBMC properties, the proposed techniques do not require side information transmission. The PAPR performance of the techniques is shown to match, or in some cases improve, on current PAPR techniques for FBMC. Initial analysis of the computational complexity of the SGP techniques indicates that the complexity issues with PAPR reduction in FBMC implementations can be addressed. The out-of-band interference introduced by the techniques is investigated. As a result, it is shown that the interference can be compensated for, whilst still maintaining decent PAPR performance. Additional results are also provided by means of a study of the PAPR reduction of the proposed techniques at a fixed clipping probability. The bit error rate (BER) degradation is investigated to ensure that the trade-off in terms of BER degradation is not too severe. As illustrated by exhaustive simulations, the SGP ACE-based technique proposed are ideal candidates for practical implementation in systems employing the low-complexity polyphase implementation of FBMC modulators. The methods are shown to offer significant PAPR reduction and increase the feasibility of FBMC as a replacement modulation system for OFDM.

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 projectiononto-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.