A Hybrid Tomlinson-Harashima Transceiver Design for Multiuser mmWave MIMO Systems.

This letter presents a new hybrid transceiver design for multiuser millimeter wave (mmWave) multiple-input–multiple-output downlink systems. To achieve improved sum-rate and error-rate performances, the proposed hybrid system is based on a combination of the Tomlinson–Harashima precoding and the block-diagonal geometric mean decomposition. With some novel observations and design choices, we showed that a closed-form solution can be obtained similarly for the hybrid design. Simulation shows the proposed design performs very close to its fully digital counterpart, and substantially outperforms the existing linear precoder-based hybrid transceivers.