A physical layer solution for Tomlinson-Harashima precoding in the framework of LTE-Advanced

Tomlinson-Harashima precoding (THP), as a suboptimal realization of dirty paper coding, has attracted extensive attentions in recent years. However, in numerous studies, only a few of them considered the limitations and restrictions in reality. In this paper, we first point out three main limitations and restrictions of THP when implementing it in the framework of a real industrial system, i.e., the Long Term Evolution Advanced (LTE-A). Then, we propose a physical layer solution for THP in LTE-A, which mainly involves the precoding schemes for Physical Downlink Shared Channel (PDSCH), User Equipment (UE) specific Reference Signal (RS), and the receiver schemes. These schemes are then evaluated by simulations. The simulation result of linear precoding zero-forcing beamforming (ZF-BF) is also provided. The result shows that THP outperforms ZF-BF mainly in high correlation scenario. In low correlation scenario, ZF-BF is better than THP in the high Signal-Noise Ratio (SNR) region.