Precoded filtered multitone with overlapping subcarriers for 5G communication systems

Filtered multitone (FMT) modulation is a promising candidate for the downlink of 5G communication systems, due to its higher spectral efficiency with respect to solutions currently adopted in 4/4.5G systems. However, design of selective FMT filters is a challenging task and their use can significantly increase implementation complexity. In this paper we propose to relax the filter design constraints by allowing partial inter channel interference (ICI). At the same time we propose to use a Tomlinson-Harashima precoding (THP) precoder to remove ICI at the transmitter, thus allowing for a simple implementation of the mobile terminal. Moreover, a bidirectional THP is considered, where the cascade of two THP structures is adopted along the subcarriers. Numerical results on relevant mobile communication scenario support the effectiveness of the proposed solution.