Research
Overview:
My research interests include wireless
communications, information theory and communication theory. Below are some of
my research projects with links to relevant publications. A chronological list
can be found in my publications
page.
·
Cooperative
Communications
·
Joint Source and
Channel Coding for Wireless Networks
·
Wireless Physical
Layer Security
·
Power Efficient
Multimedia Communications
·
Preamble and
Feedback Design in Multiple Antenna Systems
·
Spread-Spectrum
Techniques for Multiple Transmit Antennas
·
Low Complexity
Multiuser Communications
v
Cooperative
Communications
Wireless
communication systems suffer from fading and multipath distortion, as well as
interference caused by multiple users operating over a limited bandwidth. Cooperation of
users, by enabling wireless terminals to assist each other in transmitting
information to their desired destinations, provides a good solution to the
problems that current wireless technologies face. At the physical layer,
terminals overhear one another’s signals, process and retransmit to form a virtual antenna array. Through
cooperation, it is possible to obtain the spatial diversity benefits of
multi-input multi-output (MIMO) systems without necessarily having a physical
antenna array at each terminal. Furthermore, unlike MIMO systems, cooperation
is able to successfully mitigate shadow fading. Cooperative communication
techniques can easily adapt to the changing environment by opportunistically
redistributing network resources such as energy and bandwidth. Incorporating
the notion of cooperation at the medium access control (MAC) layer extends the
benefits to large networks resulting in high throughput, low delay, reduced
interference, low transmitted power and extended coverage. Cross-layer design
between the application layer and the physical layer enables high quality
multimedia transmission over cooperative wireless links.
Our work in this area spans
multiple layers of the protocol stack including physical, MAC, networking and
application layers as well as cross-layer design. We are interested the theory
of cooperative networking (such as information theoretic aspects) as well as
implementation (such as a cooperative networking testbed).
Our paper “User cooperation-diversity:
Part I and II” won 2004 Communications Society Stephen O. Rice Paper Prize in the Field of
Communications Theory, as the best original paper published in IEEE
Transactions on Communications in 2003. The paper “Diversity-multiplexing
tradeoff in half-duplex relay systems” was selected as the best paper of the
Communication Theory Symposium of ICC 2007. More information can be found in
the Cooperative Communications Laboratory
web site.
This research is partially
funded by NSF, Philips, WICAT, CATT and Othmer
Institute for Interdisciplinary Studies.
Related Publications:
Journal:
v
Submitted:
- O. Sahin, O. Simeone and E. Erkip.
Interference channel with and out-of-band relay. Under review, IEEE Transactions on Information
Theory.
- K. Bakanoglu, S. Tomasin and E. Erkip.
Resource allocation for the parallel relay channel with multiple relays. Under review, IEEE Transactions on Wireless Communications.
- O. Simeone,
E. Erkip and S. Shamai.
Robust transmission and interference management for femtocells
with unreliable network access. Under review, IEEE Journal on Selected Areas on Communications.
- O. Simeone, O. Somekh, E. Erkip, H. V.
Poor, S. Shamai. Robust communication via
decentralized processing with unreliable backhaul links. Under review, IEEE Transactions on Information
Theory.
- O. Alay, T. Korakis,
Y. Wang, E. Erkip and S. Panwar.
Layered wireless video multicast using relays. Under review, IEEE Transactions on Circuits and
Systems for Video Technology.
- F. Verde, T. Korakis,
E. Erkip and A. Scaglione.
A simple recruitment scheme of multiple nodes for cooperative MAC. Under
review, IEEE Transactions on
Communications.
v
Published / To appear:
- T. Korakis, M. Knox,
E. Erkip and S. Panwar.
Cooperative
network implementation using open source platforms. IEEE Communications Magazine, vol.
47, no. 2, pp. 134-141, February
2009.
- M. Yuksel and E. Erkip. Multi-antenna
cooperative wireless systems: A diversity multiplexing tradeoff
perspective. IEEE Transactions
on Information Theory, Special Issue on Models, Theory, and Codes for
Relaying and Cooperation in Communication Networks, vol. 53, no. 10,
pp. 3371-3393, October 2007.
- D. Gunduz and E. Erkip. Source
and channel coding for cooperative relaying. IEEE Transactions on
Information Theory, Special Issue on Models, Theory, and Codes for
Relaying and Cooperation in Communication Networks, vol. 53, no. 10,
pp. 3453-3475, October 2007.
- A. Chakrabarti,
E. Erkip, A. Sabharwal
and B. Aazhang. Code designs
for cooperative communication. IEEE Signal Processing Magazine, Special Issue
on Signal Processing for Multiterminal Communication
Systems, vol. 24, no. 5, pp.16-26, September 2007.
- H.Y. Shutoy, D. Gunduz, E. Erkip and Y.
Wang. Cooperative
source and channel coding for wireless multimedia communications. IEEE Journal on Selected Topics on
Signal Processing, Special Issue on Network-Aware Multimedia Processing and Communications, vol. 1, no. 2, pp.
295-307, August 2007.
- D. Gunduz and E. Erkip. Opportunistic
cooperation by dynamic resource allocation. IEEE Transactions on Wireless Communications, vol. 6, no. 4,
pp. 1446-1454, April 2007.
- P. Liu, Z. Tao, Z. Lin, E. Erkip
and S. Panwar. Cooperative
wireless communications: A cross-layer approach. IEEE Communications Magazine, vol. 13, no. 4, pp. 84-92,
August 2006. (invited paper).
- Z. Lin, E. Erkip and
A. Stefanov. Cooperative
regions and partner choice in coded cooperative systems. IEEE
Transactions on Communications,
vol. 54, no. 7, pp. 1323-1334, July 2006.
- A. Stefanov and E. Erkip. Cooperative
space-time coding for wireless networks. IEEE Transactions on Communications, vol. 53, no. 11, pp.
1804-1809, November 2005.
- A. Stefanov and E. Erkip.
Cooperative
coding for wireless networks.
IEEE Transactions on Communications, vol. 52, no. 9, pp. 1470-1476,
September 2004.
- A. Sendonaris, E. Erkip and B. Aazhang. User
cooperation diversity-Part I: System description. IEEE Transactions on Communications, vol. 51, no. 11, pp.
1927-1938, November 2003. (2004 Communications Society Stephen O. Rice
Paper Prize)
- A. Sendonaris, E. Erkip and B. Aazhang. User
cooperation diversity-Part II: Implementation aspects and performance
analysis. IEEE Transactions on
Communications, vol. 51, no.
11, pp. 1939-1948, November 2003. (2004 Communications Society Stephen O. Rice Paper Prize)
Book
Chapter:
- M. Yuksel
and E. Erkip. Information
Theoretical Limits on Cooperative Communications. In Cooperative Communications for Improved
Wireless Network Transmission, edited by Murat Uysal, IGI-Global , Chapter
1, pp. 1-28 2009 (invited).
- E. Erkip, A. Sendonaris, A. Stefanov and
B. Aazhang. Cooperative
Communication in Wireless Systems. In Advances in Network
Information Theory, edited by Piyush
Gupta, Gerhard Kramer and Adriaan J. van Wijngaarden, pp. 303-320, AMS DIMACS Series, 2004.
Conference:
v 2010:
- O. Simeone,
E. Erkip and S. Shamai.
Oblivious relaying for primitive interference relay channels. To appear, Proceedings of 2010 International
Zurich Seminar on Communications, Zurich, Switzerland,
March 2010 (invited).
- O. Simeone,
E. Erkip and S. Shamai.
Achievable rates for multicell systems with femtocells and network MIMO. To appear, Proceedings of 2010 International
Zurich Seminar on Communications, Zurich, Switzerland, March 2010
(invited).
- M. Yuksel, X. Liu
and E. Erkip. A
secure communication game with a relay helping the eavesdropper. In Proceedings of 2009 Information Theory Workshop, Taormina, Italy,
October 2009.
- O. Simeone, E. Erkip and S, Shamai. Robust
communications against femtocells access failure.
In Proceedings of 2009 Information Theory Workshop, Taormina, Italy,
October 2009.
- O. Sahin,
O. Simeone, E. Erkip. Interference
channel aided by an infrastructure relay. In Proceedings of IEEE International Symposium on Information Theory,
Seoul, Korea, June 2009.
- O. Simeone,
O. Somekh, E. Erkip, V. Poor, S. Shamai.
Multirelay channel with non-ergodic
link failures. In Proceedings of
2009 Information Theory Workshop, Volos, Greece,
June 2009.
- C. Nie, P. Liu, T. Korakis, E. Erkip and S. Panwar. CoopMAX: A cooperative MAC with randomized distributed
space-time coding for an IEEE 802.16 network.
In Proceedings of 2009 ICC Wireless
Networking Symposium, June
2009.
- M. Knox, E. Erkip, K.K. Singh, Cooperative
communication implementation at the physical layer. In Proceedings of 2009 Wireless and
Optical Communications Conference, Newark, NJ,
May 2009.
- O. Alay, P. Liu, Z. Guo, L. Wang, Y. Wang, E. Erkip,
S. Panwar. Cooperative
layered video multicast using randomized distributed space-time codes.
In Proceedings of INFOCOM 2009
Workshop on Mobile Video Delivery, Rio de Janeiro, Brazil,
April 2009.
- O. Alay, X.
Pan, E. Erkip, Y. Wang. Layered
randomized cooperative multicast for lossy data:
A superposition approach. In Proceedings of 2009
Conference on Information
Sciences and Systems, Baltimore, MD,
March 2009.
- O. Simeone, O. Somekh, E. Erkip, H. V.
Poor, S. Shamai (Shitz).
A broadcast
approach to robust communications over unreliable multi-relay networks.
In 2009 UCSD ITA Workshop, San
Diego, CA,
February 2009 (invited).
- O. Sahin, E. Erkip, O. Simeone. Interference
channel with a relay: Models, relaying strategies, bounds. In 2009 UCSD ITA Workshop, San
Diego, CA,
February 2009 (invited).
v 2008:
- P. Liu, Y. Liu, T. Korakis,
A. Scaglione, E. Erkip,
S. Panwar. Cooperative
MAC for rate adaptive randomized distributed space-time coding. In Proceedings of 2008 GLOBECOM Wireless Networking Symposium, New Orleans, Lousiana,
November 2008.
- O. Alay, K. Guan, Y. Wang, E. Erkip, S. Panwar, R. Ghanadan. Wireless
video multicast in tactical environments. In Proceedings of MILCOM 2008, San Diego, California,
November 2008.
- O. Sahin and E. Erkip. Cognitive
relaying with one-sided interference. In Proceedings of Forty
Second Annual Asilomar Conference on Signals,
Systems and Computers,
Pacific Grove, California, October 2008 (invited).
- O. Alay, R. Ding, E. Erkip,
Y. Wang, A. Scaglione. Layered
randomized cooperation for multicast. In Proceedings of Forty Second Annual Asilomar
Conference on Signals, Systems and Computers, Pacific Grove, California,
October 2008 (invited).
- K. Bakanoglu, S. Tomasin,
E. Erkip. Resource
allocation for the parallel relay channel with multiple relays. In Proceedings of Forty Second Annual Asilomar Conference on Signals, Systems and Computers,
Pacific Grove, California, October 2008.
- D. Gunduz, E. Erkip, A. Goldsmith and H.V. Poor. Lossy source transmission over the relay channel.
In Proceedings of IEEE International Symposium on Information Theory, Toronto, Canada, July 2008.
- F. Verde, T. Korakis,
E. Erkip and A. Scaglione.
On avoiding
collisions and promoting cooperation: Catching two birds with one stone.
In Proceedings of 2008 International Workshop on Signal Processing Advances for Wireless
Communications (SPAWC), Recife,
Brazil,
July 2008.
- O. Sahin and E. Erkip. Cooperative interference management: The role
of cognitive relaying. Presented at the 2008 IEEE Communication Theory Workshop (invited talk), St. Croix, USVI, May 2008. Click here for the
slides.
- O. Alay, T. Korakis,
Y. Wang, E. Erkip and S. Panwar.
Layered
wireless video multicast using omnidirectional
relays. To appear, Proceedings
of ICASSP, Las Vegas,
NV, April 2008.
v 2007:
- O. Sahin and E. Erkip. Achievable
rates for the Gaussian interference relay channel. In Proceedings
of 2007 GLOBECOM Communication Theory
Symposium, Washington
D.C., November 2007.
- O. Sahin
and E. Erkip. On
achievable rates for interference relay channel with interference cancellation.
In Proceedings of Forty First Annual Asilomar Conference on Signals, Systems and Computers,
Pacific Grove, California, November 2007 (invited
paper).
- O. Alay, E. Erkip and Y. Wang. Cooperative
transmission of correlated Gaussian sources. In Proceedings
of Forty First Annual Asilomar Conference on
Signals, Systems and Computers, Pacific Grove, California, November
2007.
- K.
Bakanoglu, D. Gunduz, E. Erkip. Dynamic
resource allocation for the broadband relay channel. In Proceedings of Forty First Annual Asilomar Conference on Signals, Systems and Computers,
Pacific Grove, California, November 2007.
- M. Yuksel
and E. Erkip. Secure
communication with a relay helping the wiretapper.
In Proceedings
of 2007 Information Theory Workshop, Lake Tahoe, California,
September 2007 (invited paper).
- D. Gunduz and E. Erkip. Reliable
cooperative source transmission with side information. In Proceedings
of 2007 Information Theory Workshop, Bergen, Norway, July 2007 (invited
paper).
- M. Yuksel
and E. Erkip. Diversity-multiplexing
tradeoff in half-duplex relay systems. In Proceedings of 2007 ICC Communication Theory Symposium, Glasgow, Scotland,
June 2007. (Best Paper Award, ICC 2007 Communication
Theory Symposium)
- D. Gunduz, C. T. K. Ng, E. Erkip
and A. J. Goldsmith. Source
transmission over relay channel with correlated relay side information.
In Proceedings
of IEEE International Symposium
on Information Theory, Nice, France,
June 2007.
- M. Yuksel
and E. Erkip. The relay
channel with a wiretapper. In Proceedings of 2007 Conference on Information Sciences and
Systems, Baltimore,
MD, March 2007.
- O. Sahin
and E. Erkip. Dynamic
resource allocation for multi source-destination
relay networks. In Proceedings
of 2007 Conference on Information
Sciences and Systems, Baltimore, MD,
March 2007.
v 2006:
- Z. Lin, E. Erkip and M. Ghosh. Rate
adaptation for coded cooperative systems. In Proceedings of 2006
GLOBECOM Communication Theory Symposium, San Francisco, December 2006.
- H. Shutoy,
Y. Wang and E. Erkip. Cooperative
source and channel coding for wireless video transmission. In Proceedings of IEEE International Conference on Image Processing, Atlanta, Georgia, October 2006 (invited
paper).
- M. Yuksel
and E. Erkip. Diversity-multiplexing
tradeoff in multiple-antenna relay systems.
In Proceedings of 2006 IEEE International Symposium on
Information Theory, Seattle,
July 2006.
- M. Yuksel and E. Erkip. Diversity-multiplexing
tradeoff in cooperative wireless systems. In Proceedings of the 2006 Conference on Information Sciences and
Systems, Princeton University, New Jersey, March 2006.
v 2005:
- Z.
Lin and E. Erkip. Relay search
algorithms for coded cooperative systems. In Proceedings
of 2005 GLOBECOM Communication Theory
Symposium, St. Louis, December
2005.
- M. Yuksel and E. Erkip. Can virtual MIMO mimic a multi-antenna system:
Diversity-multiplexing tradeoff for wireless relay networks. Presented at the 2005 IEEE Communication Theory Workshop (invited talk), Park City, Utah,
June 2005. Click here for the
slides.
- D. Gunduz and E. Erkip. Outage
minimization by opportunistic cooperation. In Proceedings of 2005 WirelessCom,
Symposium on Information Theory, Maui,
Hawaii, June 2005.
- Z. Lin, E. Erkip and
M. Ghosh. Adaptive
modulation for coded cooperative systems. In Proceedings of 2005 International Workshop on Signal
Processing Advances for Wireless Communications (SPAWC), New York City, June
2005.
- D. Gunduz and E. Erkip. Source and
channel coding for cooperative relaying. In Proceedings of 2005 International Workshop on Signal
Processing Advances for Wireless Communications (SPAWC), New York City, June
2005 (invited paper).
- X. Xu, D. Gunduz, E. Erkip and Y.
Wang. Layered
cooperative source and channel coding. In Proceedings of 2005 ICC Multimedia Communication
and Home Networking Symposium, Seoul,
Korea, May
2005 (invited paper).
- D. Gunduz and E. Erkip. Opportunistic
cooperation and power control strategies for delay-limited capacity.
In Proceedings of the 2005 Conference
on Information Sciences and Systems, Baltimore, March 2005.
v
2004:
- X. Xu, Y. Wang and E. Erkip. Layered
cooperation for wireless multimedia communications. In Proceedings of 2004 Picture Coding
Symposium, San Francisco,
December 2004 (invited paper).
- Z.
Lin, E. Erkip and A. Stefanov.
Cooperative
regions for coded cooperative systems. In Proceedings of 2004 GLOBECOM
Communication Theory Symposium, Dallas,
December 2004.
- M. Yuksel and E. Erkip. Broadcast
strategies for the fading relay channel. In Proceedings of 2004 Military Communications Conference, Monterey, November
2004 (invited paper).
- Z.
Lin, E. Erkip and A. Stefanov.
Exact pairwise error probability for the MIMO block fading
channel. In Proceedings of 2004
International Symposium on Information Theory and its Applications, Parma, Italy,
October 2004.
- Z.
Lin, E. Erkip and A. Stefanov.
An asymptotic
analysis on the performance of coded cooperation systems. In Proceedings of 2004 Fall Vehicular Technology
Conference, Los Angeles,
September 2004.
- D. Gunduz and E. Erkip. Joint source-channel
cooperation: Diversity versus spectral efficiency. In Proceedings of 2004 International Symposium on Information
Theory, Chicago, June 2004.
- M. Yuksel and E. Erkip. Diversity
gains and clustering in wireless relaying. In Proceedings of 2004 International
Symposium on Information Theory, Chicago, June 2004.
v
2003:
- M. Yuksel and E. Erkip. Diversity
in relaying protocols with amplify and forward.
In Proceedings of 2003 GLOBECOM Communication
Theory Symposium, San
Francisco, December 2003.
- Z. Lin, E. Erkip and
A. Stefanov. Simple
derivation of exact pairwise
error probability for Rayleigh block fading channels. In Proceedings of 41st Annual Allerton
Conference on Communication, Control and Computing, October 2003.
- A. Stefanov and E. Erkip. Cooperative Coding Theory and Applications.
Presented at the 32nd Annual IEEE
Communication Theory Workshop (invited talk), Mesa, Arizona,
April 2003.
- A. Stefanov and E. Erkip. Cooperative
Space-Time Coding for Wireless Networks. In Proceedings of IEEE Information Theory Workshop, La Sorbonne, Paris, France,
April 2003.
- A. Stefanov and E. Erkip. On the
performance analysis of cooperative space-time coded systems. In Proceedings
of IEEE Wireless Communications
and Networking Conference (WCNC 2003), New Orleans, Lousiana,
March 2003.
v
Prior
to 2003:
- A. Stefanov and E. Erkip. Cooperative
coding for wireless networks. In Proceedings
of IEEE Conference on Mobile and Wireless Communications Networks, Stockholm, Sweden, September 2002.
- A. Stefanov and E. Erkip. Cooperative
information transmission in wireless networks. In Proceedings
of 2002 Asian-European Information Theory Workshop, Breisach, Germany, June 2002.
- E. Erkip. Capacity and power
control for spatial diversity. In Proceedings
of the 2000 Conference on Information Sciences and Systems (invited
talk), pp. WA4-28/WA4-31, Princeton
University, New Jersey,
March 2000.
- A. Sendonaris, E. Erkip and B. Aazhang. Increasing
uplink capacity via user cooperation diversity. In Proceedings of 1998 IEEE International
Symposium on Information Theory, page 156, MIT, August 1998.
Back to top
v
Joint
Source and Channel Coding for Wireless Networks
Transmission of
multimedia signals over wireless networks poses several challenges that do not
exist in wired networks. Bandwidth limitations of the wireless channel,
interference from multiple users operating in the same band and channel
variations due to fading become bottlenecks for typical multimedia applications that
require high bandwidth and an error resilient communication medium.
This research
outlines a cross-layer approach between the application layer and the physical
layer to maintain desired end-to-end signal quality for multimedia transmission
over bandwidth and power limited multiuser wireless channels. The objective is
to design joint source and channel coding techniques to minimize the end-to-end
source distortion. A general source and channel separation theorem for wireless
networks does not exist; optimality of Shannon's
separate source and channel code design fails for non-ergodic
fading channels or for multiuser communication systems. On the other hand, even
when source and channel separation is not optimal, it is desirable to have only
a loose coupling between the source and channel coders to simplify the designs.
This project
addresses joint source and channel coding for the fundamental building blocks
of a wireless network, including single user (point-to-point), multiple access
and relay channels. The system model is general to encompass different
communication scenarios: Correlation among the source signals is allowed, the
receivers may have correlated side information, the channel can be
time-invariant or fading may be present, links can have multiple degrees of
freedom such as multiple antennas or multiple fading blocks. This project
investigates the design of optimal joint source and channel coding strategies,
and performance improvements when minimal interaction among the source and
channel coders is allowed. The goal is to discover scenarios under which
separation is optimal, or close to optimal.
Our project also
considers practical applications, in particular unicast
and multicast wireless video. The emphasis is on cross-layer design to improve
the quality of wireless video transmission using cooperative networking.
One of our papers
in this area, “Minimum expected distortion in Gaussian joint source-channel
layered broadcast coding with successive refinement,” was selected for the
Student Paper Award at ISIT 2007.
This research is partially funded by NSF, Philips
and WICAT.
Related
Publications:
(Publications that consider source and channel coding with
relaying/cooperation can be found under “Cooperative Communications”
project)
Journal:
v
Published / To appear:
- J. Nayak, E. Tuncel, D. Gunduz and E. Erkip. Successive refinement of vector sources under
individual distortion criteria. To appear, IEEE
Transactions on Information Theory.
- C.T. K. Ng, D. Gunduz, A.J. Goldsmith and E. Erkip. Optimal power
distribution and minimum expected distortion in Gaussian layered broadcast
coding with successive refinement. IEEE
Transactions on Information Theory, vol.55, no. 10, pp.5074-5086, November 2009.
- D. Gunduz, E. Erkip, A. Goldsmith and H. V.
Poor. Source
and channel coding for correlated sources over multi-user channels. IEEE Transactions on
Information Theory, vol.55, no. 9, pp. 3927-3946,
September 2009.
- D. Gunduz
and E. Erkip. Joint source
channel codes for MIMO block fading channels. IEEE Transactions on Information Theory, vol. 54, no. 1, pp 116-134,
January 2008.
Conference:
v 2008:
v 2007:
- J. Nayak, E. Tuncel, D. Gunduz, and E. Erkip. Successive
refinement of vector sources under individual distortion criteria. In Proceedings of 2007 Information Theory
Workshop, Lake Tahoe,
California, September 2007
(invited paper).
- C. T. K. Ng, D. Gunduz, A. J. Goldsmith and E. Erkip.
Minimum
expected distortion in Gaussian joint source-channel layered broadcast
coding with successive refinement. In Proceedings of IEEE International Symposium on
Information Theory, Nice, France, June 2007. (ISIT Student Paper Award)
- D. Gunduz
and E. Erkip. Interference
channel and compound MAC with correlated sources and receiver side
information. In Proceedings of IEEE
International Symposium on Information Theory, Nice, France,
June 2007.
- C. T. K. Ng, D. Gunduz,
A. J. Goldsmith and E. Erkip. Recursive power
allocation in Gaussian joint source-channel layered broadcast coding.
In Proceedings of 2007 ICC
Communication Theory Symposium, Glasgow,
Scotland,
June 2007.
- D. Gunduz and E. Erkip. Lossless
transmission of correlated sources over a multiple access channel with
side information. In Proceedings
of Data Compression Conference,
Snowbird, Utah,
March 2007.
- D. Gunduz
and E. Erkip. Correlated
sources over an asymmetric multiple access channel with one distortion
criterion. In Proceedings of
2007 Conference on Information Sciences and
Systems, Baltimore,
MD, March 2007.
v 2006:
v 2005:
Back to top
v
Wireless
Physical Layer Security
Related
Publications:
(Publications that consider physical layer security for
relaying/cooperation can be found under “Cooperative Communications”
project)
Journal:
v
Submitted:
Book
Chapter:
- D. Gunduz,
E. Erkip and H.V. Poor. Source Coding
Under Security Constraints. To appear in Securing Wireless Communications at the Physical Layer, edited
by Wade Trappe and Ruoheng Liu, Springer-Verlag, 2010 (invited).
Conference:
v 2008:
Back to top
v
Power
Efficient Multimedia Communications
Energy management in portable
multimedia communications devices is becoming more and more critical and
complex, with the convergence of computing and communication technologies,
particularly when video signal processing and secure communications are
integrated. There are many demands on the power supply of a portable
information device, including the power supply, display, signal processing
hardware, and modem. Our research attempts to prolong battery life by adapting the
signal processing, radio transmission, encryption, and battery discharge
operations of a wireless terminal to changing operating conditions. The
operating conditions include wireless channel quality, network activity, and
remaining battery charge.
Our recent work provides an
approach for minimizing the total power consumption of a mobile transmitter due
to source compression, channel coding and transmission subject to fixed
end-to-end source distortion. We have illustrated,
both in an abstract setting and in a realistic H.263 compressed video over
wireless, that an optimized system which adapts the transmission power,
compression, and channel coding parameters to the channel conditions and the
implementation platform prolongs the battery life considerably. We have also
investigated the effects of multiple interfering users on the power
optimization problem, and how simultaneous transmission of video and data can
be accomplished in a power limited environment.
This research is a collaborative
effort among five Polytechnic faculty with diverse
relevant research interests. More
information on this collaboration can be found in the DREAM-IT (Dynamically Reconfigurable
Energy Aware Multimedia Information Terminals) project web page.
This project is partially funded
by NSF ITR and Research Instrumentation Programs and WICAT.
Related Publications:
Journal:
- X. Lu, Y. Wang, E. Erkip
and D. Goodman. Total power
minimization for multiuser video communications over CDMA networks. IEEE
Transactions on Circuits and Systems for Video Technology, vol. 17, no. 6, pp. 674-685, June 2007.
- X. Lu, E. Erkip, Y.
Wang and D. Goodman. Power efficient
multimedia communication over wireless channels. IEEE Journal on Selected Areas on Communications, Special Issue on
Recent Advances in Wireless Multimedia, vol.21, no. 10, pp.1738-1751,
December 2003.
Book Chapter:
- E. Erkip, X. Lu, Y. Wang, D. Goodman. Total
power optimization for wireless multimedia communication. In System Level Power Optimization for
Wireless Multimedia Communication: Power Aware Computing, edited by R.
Karri and D. Goodman, Chapter 1, Kluwer Academic
Publishers, 2002. Conference version presented in IMPACCT 2002, Integrated
Management of Power Aware Communications, Computing and Networking
Workshop, in conjunction with ICC 2002, New York, New York, May 2002.
Conference:
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v
Preamble
and Feedback Design in Multiple Antenna Systems
Most practical systems provide channel estimation at the receiver
through preambles. Furthermore, this information can be partially relayed to the
transmitter through some kind of feedback, in the form of ARQ or power control.
However, it is not clear how effective these ad-hoc channel estimation and
feedback methods are in utilizing network resources, what losses are incurred
by imperfect or finite rate estimation and feedback strategies and how the
transmitter and receiver should be designed based on partial channel estimation
and feedback. These issues are especially relevant for multiple-antenna systems
where considerable gains can be achieved via feedback.
We have recently studied achievable rates for some practical
multi-antenna preamble and feedback strategies. We have also provided
analytical bounds on the outage probability for finite rate feedback and
illustrated how one can design good beamformers based
this finite rate feedback for multiple transmit antennas.
This research is carried in collaboration with Rice University
and partially
funded by NSF.
Related Publications:
Journal:
Conference:
Back to top
v
Spread-Spectrum
Techniques for Multiple Transmit Antennas
Related
Publications:
Journal:
Conference:
Back to top
v
Low
Complexity Multiuser Communications
Related
Publications:
Journal:
Conference:
Back to top