Coordinate Tomlinson-Harashima Precoding Design for Overloaded Multi-user MIMO Systems

TL;DR

This paper introduces an iterative coordinate THP algorithm for overloaded multi-user MIMO systems, overcoming dimensionality constraints and improving BER and sum-rate performance.

Contribution

The paper proposes a novel iterative coordinate THP algorithm applicable when receive antennas exceed transmit antennas, enhancing performance in overloaded MIMO scenarios.

Findings

Significant BER improvement over previous methods

Enhanced sum-rate performance in simulations

Effective for overloaded multi-user MIMO systems

Abstract

Tomlinson-Harashima precoding (THP) is a nonlinear processing technique employed at the transmit side to implement the concept of dirty paper coding (DPC). The perform of THP, however, is restricted by the dimensionality constraint that the number of transmit antennas has to be greater or equal to the total number of receive antennas. In this paper, we propose an iterative coordinate THP algorithm for the scenarios in which the total number of receive antennas is larger than the number of transmit antennas. The proposed algorithm is implemented on two types of THP structures, the decentralized THP (dTHP) with diagonal weighted filters at the receivers of the users, and the centralized THP (cTHP) with diagonal weighted filter at the transmitter. Simulation results show that a much better bit error rate (BER) and sum-rate performances can be achieved by the proposed iterative coordinate THP compared to the previous linear art.