Abstract: OFDM (orthogonal frequency division multiplexing) is by far the most important modulation technique for broadband wireless communication systems. In OFDM signaling subsequent symbols are separated by guard intervals which are usually implemented as cyclic prefixes (CPs). In this plenary lecture we present a novel transmit signal structure and an adjusted and optimized receiver for OFDM. Instead of the conventional cyclic prefix we use a deterministic sequence, which we call unique word (UW), as guard interval. We show how unique words, which are already well investigated for single carrier systems with frequency domain equalization (SC/FDE), can also be introduced in OFDM symbols. Since unique words represent known sequences, they can advantageously be used for synchronization and channel estimation purposes. Furthermore, the proposed approach introduces correlations between subcarrier symbols, which allows to apply a highly efficient Wiener LMMSE (linear minimum mean square error) estimator at the receiver. We present simulation results in an indoor multipath environment to highlight the advantageous properties of the proposed scheme.

Brief Biography of the Speaker:
Mario Huemer was born in Wels, Austria in 1970. He received the Dipl.-Ing. degree in mechatronics and the Dr.techn. (Ph.D.) degree from the Johannes Kepler University of Linz, Austria, in 1996 and 1999, respectively. From 1997 to 2000, he was a scientific assistant at the Institute for Communications and Information Engineering at the University of Linz, Austria. From 2000 to 2002, he was with Infineon Technologies Austria, research and development center for wireless products. From 2002-2004 he was a Professor for Communications and Information Engineering at the University of Applied Sciences of Upper Austria, from 2004-2007 he was Associate Professor for Electronics Engineering at the University of Erlangen-Nuremberg, Germany. In 2007, he has moved to Klagenfurt, Austria, to overtake the Directorship of the Chair for Embedded Systems and Signal Processing at the University of Klagenfurt as a Full Professor. He has been engaged in research and development on WLAN, wireless cellular, and wireless positioning systems, and on highly integrated baseband and RF ICs for mobile devices. Within these fields he published more than 110 papers. His current research interests are focused on real time signal processing algorithms and architectures for embedded applications. Dr. Huemer is member of the IEEE Signal Processing Society, IEEE Communications Society and the IEEE Circuits and Systems Society. He is also member of the European Association for Signal Processing (EURASIP), the German Information Technology Society (ITG) in the Association for Electrical, Electronic & Information Technologies (VDE) and the Austrian Electrotechnical Association (OVE).