Decentralization of Tomlinson-Harashima Precoding for MU-MIMO System

Multi-User Multiple-Input Multiple-Output (MU-MIMO) antenna arrays are considered a crucial technology for future wireless communication systems. However, precoding for MU-MIMO meets significant challenges. To tackle this issue, this paper introduces a novel star decentralized precoding algorithm, aiming to decentralize part of the precoded calculations from the central unit (CU) to the decentralized units (DUs) and reduce the computational complexity of the CU. Then, we apply the Zero Forcing Tomlinson-Harashima precoding (ZF-THP) algorithm to star decentralized baseband processing (DBP) for enhanced transmission rate, and this algorithm has the same performance as centralized precoding but with reduced CU complexity. Furthermore, we propose the star decentralized minimum mean square error THP (sDMMSE-THP) algorithm to enhance system performance further. Extensive simulation data validate the effectiveness of our proposed scheme.