A PAPR Reduction Method for FMT Based on Randomly Assigned Prototype Filters

As one type of filter bank multicarrier (FBMC), Filtered Multitone Modulation (FMT) suffers from an excessively high peak-to-average power ratio (PAPR), despite offering advantages over Orthogonal Frequency Division Multiplexing (OFDM) such as lower out-of-band power leakage, reduced sensitivity to frequency offsets and stronger resistance to inter-carrier interference (ICI). The elevated PAPR can induce nonlinear distortion in power amplifiers, severely degrading the practical performance of communication systems and significantly hindering the real-world engineering applications of this technology. To address this issue, this paper proposes a new method of Randomly Assigned Prototype Filter to reduce PAPR in FMT systems. Due to the flexible options of prototype filter in FMT, this method randomly assigns different prototype filters to subcarriers and multiplies them by phase rotation factors, to adjust phase coherence during FMT signal superposition. Simulation results demonstrate that compared to traditional PAPR reduction algorithms, the RAPF method can significantly reduce out-of-band leakage and effectively lower PAPR in FMT system with manageable computational complexity. This advancement enhances the practicality of FMT for wireless communication applications in the future.