Select a calendar:
Filter November Events by Event Type:
SUNMONTUEWEDTHUFRISAT
Events for November 01, 2013
-
Two New Approaches to Massive MIMO
Fri, Nov 01, 2013 @ 11:00 AM - 12:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Speaker: Ralf Mueller, FAU Erlangen-Nuremberg
Talk Title: Two New Approaches to Massive MIMO
Abstract: Massive MIMO systems are promising for solving the wireless bottleneck. Still some fundamental issues in massive MIMO are open. In this talk two of them are addressed: 1) The channel estimation problem which is often referred to as "pilot contamination". 2) The cost scaling problem which arises from the massive use of analog hardware. Concerning 1), a system design based on power-controlled handover and non-linear channel estimation is proposed. In particular, the signal subspaces occupied by intercell and intracell users are blindly separated by means of singular value decomposition. Concerning 2), a new hardware structure to generate RF signals is proposed. This structure avoids mixers and the need for linear power amplifiers. It consists of a single RF oscillator common to all antenna elements that is driving varying imaginary impedances and makes use of the law of large numbers for impedance matching.
Biography: Prof. Müller was born in Schwabach, Germany, 1970. He received the Dipl.-Ing. and Dr.-Ing. degree with distinction from the Friedrich-Alexander-University (FAU) Erlangen-Nuremberg in 1996 and 1999, respectively. From 2000 to 2004, he directed a research group at Vienna Telecommunications Research Center in Vienna, Austria and taught as an adjunct professor at Vienna University of Technology. In 2005, he was appointment full professor at the Department of Electronics and Telecommunications at the Norwegian University of Science and Technology in Trondheim, Norway. In 2013, he joined the Institute for Digital Communications at FAU Erlangen-Nuremberg in Erlangen, Germany. He held visiting appointments at Princeton University, US, Institute Eurecom, France, University of Melbourne, Australia, University of Oulu, Finland, National University of Singapore, Babes-Bolyai University, Cluj-Napoca, Romania, Kyoto University, Japan, FAU Erlangen-Nuremberg, Germany, and Munich University of Technology.
Prof. Müller received the Leonard G. Abraham Prize (jointly with Sergio Verdú) for the paper "Design and analysis of low-complexity interference mitigation on vector channels'' from the IEEE Communications Society. He was presented awards for his dissertation "Power and bandwidth efficiency of multiuser systems with random spreading'' by the Vodafone Foundation for Mobile Communications and the German Information Technology Society (ITG). Moreover, he received the ITG award for the paper "A random matrix model for communication via antenna arrays,'' as well as the Philipp-Reis Award (jointly with Robert Fischer). Prof. Müller served as an associate editor for the IEEE Transactions on Information Theory from 2003 to 2006
Host: Giuseppe Caire, caire@usc.edu, EEB 540, x04683
Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248
Audiences: Everyone Is Invited
Contact: Gerrielyn Ramos
-
Integrated Systems Seminar Series
Fri, Nov 01, 2013 @ 03:30 PM - 05:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Speaker: Prof. Harish Krishnaswamy, Columbia University
Talk Title: Power Generation in CMOS from RF to THz: A Spectrum of Challenges and Opportunities
Series: Integrated Systems Seminar Series
Abstract: Technology scaling has enabled CMOS to serve as a platform for the implementation of a wide range of wireless systems operating from radio frequencies to terahertz. However, while we have seen steady (actually, somewhat slowing) increases in speed with technology scaling, this has been accompanied by the inevitable shrinking of supply and breakdown voltages. Consequently, power generation in CMOS is plagued by fundamental trade-offs between output power, efficiency, fidelity and operating frequency. The RF, millimeter-wave and terahertz frequency ranges represent different points in this multi-dimensional trade-off, but each is faced with fundamental challenges dictated by application requirements.
mmWave power amplifiers have traditionally been limited to output power levels that are lower than 100mW and efficiencies lower than 20% due to the need to use scaled technologies with low supply voltages of around 1V. In this presentation, I will describe techniques developed at Columbia University, including device stacking, switch-mode operation at mmWave and low-loss on-chip power combining, that have enabled the first watt-class mmWave PA in CMOS.
At RF frequencies, speed can be traded-off for output power and consequently, watt-level output power is relatively straightforward. However, precision and signal fidelity, manifested as out-of-band emissions, are fundamental challenges, particularly for reconfigurable radios with reduced front-end filtering. This presentation will cover techniques recently developed at Columbia for receiver-band noise filtering in watt-level "digital PAs" and active cancellation of transmitter leakage and noise in reconfigurable receivers. These techniques enable frequency-division-duplexing in reconfigurable radios with relaxed transmitter-receiver isolation.
Finally, terahertz frequencies lie beyond the maximum operating frequencies of today's CMOS devices. I will briefly touch upon techniques that leverage device non-linearity to enable terahertz signal generation in CMOS in the milliwatt power envelope.
Biography: Harish Krishnaswamy received the B.Tech. degree in Electrical Engineering from the Indian Institute of Technology-Madras, India, in 2001, and the M.S. and Ph.D. degrees in Electrical Engineering from the University of Southern California (USC) in 2003 and 2009, respectively. He joined the EE department of Columbia University as an Assistant Professor in 2009. His research group at Columbia, funded by various federal agencies, including NSF and DARPA, and industry, focuses on various topics related to devices, circuits and systems for wireless communication, radar, imaging and sensing in the RF, millimeter-wave and terahertz frequency ranges. He received the IEEE International Solid State Circuits Conference (ISSCC) Lewis Winner Award for Outstanding Paper in 2007. He also received the Best Thesis in Experimental Research Award from the USC Viterbi School of Engineering in 2009, and the DARPA Young Faculty Award in 2011
Host: Hossien Hashemi, Mike Chen, Mahta Moghaddam, Kunal Datta
More Info: http://mhi.usc.edu/activities/integrated-systems/
More Information: Harish Krishnaswamy_Flyer.pdf
Location: Hughes Aircraft Electrical Engineering Center (EEB) - EEB 248
Audiences: Everyone Is Invited
Contact: Danielle Hamra
Event Link: http://mhi.usc.edu/activities/integrated-systems/
