Robust Tomlinson-Harashima Precoding

Frank A. Dietrich, Wolfgang Utschick

Abstract: Tomlinson-Harashima Precoding (THP) for a wireless system with multiple cooperative transmitters and non-cooperative receivers is considered (downlink channel). In the literature THP has been optimized for this channel assuming complete channel state informatioin (CSI). But quality of CSI is generally poor at the transmitter due to the timevarving channel. We present a robust optimization of THP and a combined optimizlation of THP and channel estimation, which take into account the quality of CSI. They yield a significantly improved robustness towards errors in CSI.