MIMO receivers using soft information

Multiple input multiple output (MIMO) wireless systems that use multiple transmit and receive antennas allow a gain in reliability (diversity gain) and capacity (multiplexing gain). Unfortunately, these advantages come at the cost of higher computational complexity, particularly when using soft detection (SD). SD features improved performance compared to hard detection and is a prerequisite for iterative receiver structures (turbo receivers). In this thesis we consider the sphere decoder for soft-output MIMO detection and present modifications that allow flexible trade-offs between computational complexity on the one hand and performance and diversity on the other hand. Additionally to these two modifications we present a lower bound on partial sphere decoder metrics that allows to reduce the complexity of the detection using the sphere decoder without performance degradation.

Autorentext

Günter Reise received the Dipl.-Ing. and Dr. techn. degree in electrical engineering from the Vienna University of Technology, Vienna, Austria, in 2007 and 2011, respectively, where he was a Research Assistant as well.His research interests are in signal procecssing for MIMO communication and for wireless sensor networks.