Degrees of Freedom for Mutually Interfering Broadcast Channels

Inkyu Lee,
Korea UniversityAbstract: In this talk, we present an expression of spatial degrees of
freedom (DOF) for two mutually interfering broadcast channels (IFBC) as
a function of arbitrary numbers of transmit antennas and users. The
lower bound on the DOF is obtained by showing that the zero-forcing
solution suffices to achieve all the DOF. Also, the upper bound which
coincides with the lower bound is shown using Jafar's earlier work. From
the derived result, we observe that disabling receive cooperation of the
MIMO interference channel causes the DOF loss. Additionally, we propose
a linear precoding scheme for the IFBC by extending one designed for
broadcast channels with an aim of maximizing the sum rate performance.
We utilize the fact that the precoding matrices in stationary point
always satisfy the zero-gradient condition. Our result is confirmed
through numerical simulations on the sum rate performance of the
proposed precoding technique.Biography: Inkyu Lee is currently a visiting scholar at USC. Prof. Lee
received the B.S. degree (Hon.) in control and instrumentation
engineering from Seoul National University, Seoul, Korea in 1990, and
the M.S. and Ph.D. degrees in electrical engineering from Stanford
University in 1992 and 1995, respectively. From 1995 to 2001, he was a
Member of Technical Staff at Bell Laboratories, Lucent Technologies,
where he studied high-speed wireless system design. He later worked for
Agere Systems (formerly the Microelectronics Group of Lucent
Technologies), Murray Hill, NJ, as a Distinguished Member of Technical
Staff from 2001 to 2002. In September 2002, he joined the faculty of
Korea University, Seoul, Korea, where he is currently a Professor in the
School of Electrical Engineering. His research interests include digital
communications, signal processing, and coding techniques applied to
wireless systems with an emphasis on MIMO-OFDM. Dr. Lee currently serves
as an Associate Editor for the IEEE TRANSACTIONS ON COMMUNICATIONS and
the IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS. Also, he has been a
Chief Guest Editor for the IEEE JOURNAL ON SELECTED AREAS IN
COMMUNICATIONS (Special Issue on 4G Wireless Systems).Host: Giuseppe Caire, caire@usc.edu, EEB 528, x07326

Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248

Audiences: Everyone Is Invited

Contact: Gerrielyn Ramos