Alumni Seminar – Krishna Narayanan

Date/Time
Date(s) - 11 Apr 2014
1:10 PM - 2:00 PM

Location
3043 ECpE Building Addition

Title: Physical Layer Network Coding for Wireless Networks

Krishna Narayanan

Krishna Narayanan

Speaker: Krishna Narayanan, Professor of Electrical and Computer Engineering, Texas A&M University

Abstract: Network coding is a remarkable development in the field of communications/networking which has been shown to provide significant gains in some networking scenarios. The main idea of network coding is to allow intermediate  nodes in a network to mix or combine packets before forwarding them. When network coding is considered in traditional wireline networks, this mixing usually involves computing functions (for example, XOR) of packets over finite fields and is performed at the network layer.

The incorporation of network coding into wireless networks has been an active area of interest for the past 10-15 years. Inherently, a wireless network is a combination of broadcast and superposition (or, multiple access) channels. i.e., when multiple nodes transmit signals simultaneously, a receiver naturally receives the superposition (or mixture) of the transmitted signals. Traditionally, this interference caused by multiple transmissions has been treated as being harmful and multiple access schemes have been devised to prevent such interference and create bit pipes at the physical layer. However, carefully exploiting the interference from the multiple transmissions turns out to be the key to drastically improving the performance of network coding in wireless networks.

Thus, new view of wireless networks is now emerging where the superposition nature of the network is viewed as an opportunity to mix or combine packets directly at the physical layer. Techniques that exploit this opportunity to implement network coding directly at the physical layer are called physical layer network coding techniques.

In this talk, I will discuss the main idea behind physical layer network coding and highlight the important role played by linear/lattice codes for implementing physical layer network coding. I will also discuss various other scenarios where ideas from physical layer network coding are applicable. These include relay networks, multiple-input multiple-ouput (MIMO) detection, equalization, interference channels and distributed source coding.

Speaker Bio: Krishna Narayanan is an alumnus of ISU having graduated with an M.S. degree in 1994. He then obtained his Ph.D. degree from Georgia Tech in 1998. Since then, he has been with the department of Electrical and Computer Engineering at Texas A&M University, where he is currently a Professor. His research interests are coding theory, information theory and signal processing with applications to wireless communications and data storage. He was the recipient of the 2001 National Science Foundation CAREER award and 2006 IEEE signal processing for data storage best paper award.  He was the recipient of the Association of former students college level teaching award at Texas A&M University in 2012.  He served as the area editor for coding theory and applications for the IEEE Transactions on Communications from 2007-2011. 

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