SDMA for filterbank with Tomlinson Harashima precoding

Several studies have revealed that OFDM is outperformed in several areas by the filter bank based multicarrier (FBMC) modulation thanks to pulse shaping techniques. Nevertheless, the combination of FBMC with multi-antenna architectures is nontrivial. Aiming at making progress towards this direction we study MIMO precoding techniques for the MISO broadcast channel (MISO-BC). Due to its superior performance over linear precoding techniques we have focused on the spatial Tomlinson Harashima precoder (STHP). The analysis carried out in this paper concludes that the conventional STHP performs poorly when it is combined with FBMC systems since it is not able to cope with ISI and ICI. To combat the interferences we propose a novel subband processing based on the STHP concept. The numerical results show that FBMC and OFDM almost give the same performance in terms of BER. However, FBMC is able to achieve spectral efficiency values that are 31% higher in comparison to the ones obtained in OFDM when 20% of the symbol duration corresponds to the cyclic prefix.