Systems Seminar
A Low-Complexity Receiver for OFDM in Doubly-Selective Channels
Prof. Philip Schniter
Department of Electrical Engineering
The Ohio State University
Abstract
Orthogonal frequency division multiplexing (OFDM) is a convenient
technique for communication over multipath channels with large delay
spread.
In OFDM, high-rate data is transmitted in parallel using a large
number of low-rate narrowband subcarriers, thereby preventing the
manifestation of inter-symbol interference that would otherwise result
from the dispersive channel.
OFDM is made practical by the fast Fourier transform (FFT), which
offers a computationally efficient way to modulate data onto the
orthogonal narrowband subcarriers.
When OFDM systems with large FFT length are used in fast-fading
multipath channels, however, orthogonality is lost and significant
inter-carrier interference (ICI) may result.
Due to the large FFT size, the standard approaches to data detection
in the presence of ICI (e.g., maximum likelihood, minimum mean-squared
error, or zero-forcing methods) become prohibitively complex.
To tackle this problem, we propose a detection strategy based on
optimal linear pre-processing and iterative MMSE estimation.
In addition to significant computational savings, simulation results
indicate performance that far surpasses the linear MMSE detector.
Bio
Philip Schniter was born in Evanston, IL in 1970.
He received the B.S. and M.S. degrees in Electrical and
Computer Engineering from the University of Illinois at
Urbana-Champaign in 1992 and 1993, respectively.
In 2000, he received the Ph.D. degree in Electical Engineering
from Cornell University in Ithaca, NY.
From 1993 to 1996 he was employed by Tektronix Inc. in Beaverton,
OR as a systems engineer.
There he worked on signal processing aspects of video
and communications instrumentation design, including algorithms,
software, and hardware architectures.
He is currently an Assistant Professor in the Department of Electrical
Engineering at The Ohio State University in Columbus, OH.
His research focuses on signal processing for communication
systems and wireless sensor networks.
While pursuing his Ph.D. degree, he received the 1998 Schlumberger
Fellowship and the 1998-99 Intel Foundation Fellowship.
He was awarded the 1999 Prize Paper Award from the IEEE Energy
Development and Power Generation Committee for work relating to his
M.S. thesis.
He received the NSF Career Award in 2003.
Time and Place: Wed., Mar. 26, at 1 pm in 4610 Engr. Hall.
*** NOTE SPECIAL TIME ***
SYSTEMS SEMINAR WEB PAGE:
http://www.cae.wisc.edu/~gubner/seminar/