A Novel Nonlinear Precoding Algorithm for the Downlink of Multiple Antenna Multi-User Systems

摘要

By pre-equalizing inter-stream interference at the transmitter, Tomlinson–Harashima precoding (THP) algorithm provides a solution for the downlink of multiple antenna multi-user systems, in which the decentralized structure of the receivers makes the receiver-processing impossible. However, for the zero-forcing (ZF) THP algorithm available in the literature there are significant performance differences between specific mobile stations. In this paper, a novel version of the THP algorithm is proposed. It greatly improves the worst mobile's performance and ensures balanced performance of all the mobiles. For the new THP algorithm, better performance can be obtained by suitably ordering the rows of the channel matrix. We show that the “best-first” ordering method achieves optimal order for BER performance in systems with two mobile stations and achieves near optimal order in systems with more than two mobile stations. Simulation is used to show the advantages of the new THP algorithm and the “best-first” ordering method.