Modified Tomlinson Harashima Precoding Using Square Root for Multi-User MIMO Systems

Tomlinson Harashima Precoding (THP) for Multi-User Multiple Input Multiple Output (MU-MIMO) system has been proposed as an effective way to achieve near capacity to the theoretical limit in MU-MIMO channels. In order to achieve better performance, other THP methods such as minimum mean square error (MMSE) THP and lattice reduction aided (LRA) THP are proposed. Those methods outperform the conventional THP, however, the computational complexity also increases. In this paper, we propose a modified THP by new approach using square root with less increase of computational complexity. Computer simulation shows that proposed method can achieve better trade-off between bit error rate and computational complexity than MMSE THP and LRA THP.