Noncoherent Decision-Feedback Equalization in Massive MIMO Systems

Prof. Dr.-Ing. Robert Fischer

Universität Ulm

Abstract:

We discuss noncoherent receivers in multi-user massive MIMO uplink systems. On the one hand, sorted decision-feedback differential detection (DFDD) is attractive for the detection of a particular user over a transmission burst. On the other hand, we present a noncoherent approach to decision-feedback equalization (DFE) over the users. Thereby, the contradicting principles of DFE, where interference of already detected symbols is canceled using actual channel knowledge, and noncoherent reception, where the symbols are detected without any channel-state information, are combined. Based on an analysis of the statistics of the interference terms in autocorrelation-based noncoherent receivers, DFE is proposed and optimized. Moreover, we discuss a joint user/temporal detection with optimized sorting and an iterative scheme. Numerical results quantifying the performance of the noncoherent schemes relative to coherent BLAST, taking the non-perfect channel knowledge due to finite-length training sequences into account, are presented.

Biography:

Robert Fischer received the Dr.-Ing. degree in 1996, and the habilitation degree in 2001, from the University of Erlangen-Nürnberg, Erlangen, Germany. During 1997, he held a PostDoc position at IBM Research Laboratory, Zürich, Switzerland. In 2005 he spent a sabbatical at ETH, Zürich, Switzerland. Since 2011, he has been full professor at the University of Ulm, Germany.

Dr. Fischer received the Dissertation Award form the Technische Fakultät, University of Erlangen-Nürnberg, in 1997, the Publication Award of the German Society of Information Techniques (ITG) in 2000, the Wolfgang Finkelnburg habilitation award in 2002, and the Philipp-Reis-Preis in 2005. He is author of the textbook "Precoding and Signal Shaping for Digital Transmission" (John Wiley & Sons, New York, 2002).