THP Transceiver Design for MIMO Relaying with Direct Link and Partial CSI

In this letter we consider Tomlinson Harashima precoding (THP) for multiple-input multiple-output (MIMO) relay systems with a direct link between the source and destination. It is assumed that the destination can acquire full channel state information (CSI) of all channels, whereas the source and relay have full CSI of the source-relay channel but only acquire statistical knowledge of the source-destination and relay-destination channels. Simulation results demonstrate that, for high signal to noise ratio (SNR) in the relay-destination link, the performance of the proposed design approaches that of non-linear transceivers utilising full CSI.