Power Allocation Algorithms for ZF-THP Sum Rate Optimization in Multi-User Multi-Antenna Systems

In this paper, we study a power allocation technique for Tomlinson-Harashima precoding (THP) in multi- user multiple input single output (MISO) downlink systems. In contrast to previous approaches, a mutual information based method is exploited for maximizing the sum rate of zero-forcing THP systems. Then, we propose a simple power allocation algorithm which assigns proper power level for modulo operated users. Simulation results show that the proposed scheme outperforms a conventional water-filling method, and achieves near optimal performance with much reduced complexity.